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    Tytuł:
    Study of the Magnetization Processes in Amorphous and Nanocrystalline FINEMET by the Numerical Decomposition of the Hysteresis Loops
    Autorzy:
    Kováč, J.
    Novák, L.
    Varga, L.
    Powiązania:
    https://bibliotekanauki.pl/articles/1032185.pdf
    Data publikacji:
    2017-04
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.60.-d
    75.60.Ej
    Opis:
    The magnetization processes in amorphous and nanocrystalline FINEMET ribbons were studied by the numerical decomposition of the quasi-static hysteresis loop to the contributions of the domain wall movement, the domain rotations, and the domain wall annihilation and nucleation processes following the hyperbolic T(x) model of hysteresis. The hysteresis data measured during decrease of the excitation magnetic field were used for the separation of these processes. The significant differences in behavior of these two materials were found. In amorphous state the domain rotations component dominates whereas in nanocrystalline state the domain wall movement component prevails. These differences are reflected in the anisotropy field distributions as well.
    Źródło:
    Acta Physica Polonica A; 2017, 131, 4; 732-734
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    A Comparison of Different Estimation Methods for Hysteresis Modelling
    Autorzy:
    Jastrzębski, R.
    Chwastek, K.
    Biondić, I.
    Miličević, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/1030241.pdf
    Data publikacji:
    2017-05
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.60.-d
    75.60.Ej
    Opis:
    The paper focuses on the estimation techniques for a low-dimensional phenomenological model of ferromagnetic hysteresis proposed by the Brazilian research group GRUCAD. The description is expressed with an ordinary differential equation and some auxiliary relationships. It describes both irreversible and reversible magnetization processes and addresses some problems inherent in the well-known Jiles-Atherton model. It is found that the differential evolution method is the most competitive technique for recovery of optimal model parameters.
    Źródło:
    Acta Physica Polonica A; 2017, 131, 5; 1228-1231
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Jiles-Atherton Magnetic Hysteresis Parameters Identification
    Autorzy:
    Pop, N.
    Caltun, O.
    Powiązania:
    https://bibliotekanauki.pl/articles/1493619.pdf
    Data publikacji:
    2011-09
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.60.-d
    75.60.Ej
    Opis:
    This paper presents a method of fitting the magnetic hysteresis curves using a calculating algorithm within a computer programme. The calculating programme uses the equations of the Jiles-Atherton model to simulate the M(H) magnetization curve. The aim of this program is to find the values of the parameters which are part of the Jiles-Atherton model once the regression curve for a major magnetization curve obtained experimentally is found. The values of these parameters can be increased or decreased gradually. The parameters modification takes place in such a way that the root mean square deviation between the points of the two graphs, also experimentally simulated, should decrease gradually and, in the end, it should be found below the preestablished percentage value in comparison to the previous value. The procedure for minimizing the root mean square deviation has as a result the fact that the simulated curve represents the regression curve. The calculating programme considers a second method of calculating the values of the parameters by using the already found regression curve. This paper also presents the values of the Jiles-Atherton model parameters obtained by fitting the magnetization curves of several cobalt ferrites samples, sintered at different temperatures.
    Źródło:
    Acta Physica Polonica A; 2011, 120, 3; 491-496
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Correlation between Barkhausen Noise and Coercivity in Amorphous and Nanocrystalline Fe-Cu-Nb-Si-B Alloys
    Autorzy:
    Małkiński, L.
    Kulik, T.
    Powiązania:
    https://bibliotekanauki.pl/articles/1955839.pdf
    Data publikacji:
    1997-02
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.60.-d
    75.60.Ej
    Opis:
    Samples of amorphous and nanocrystalline alloys were prepared by proper annealing of the metallic glasses: Fe$\text{}_{73.5}$Cu$\text{}_{1}$Nb$\text{}_{3}$Si$\text{}_{13.5}$B$\text{}_{9}$ and Fe$\text{}_{73.5}$Cu$\text{}_{1}$Nb$\text{}_{3}$Si $\text{}_{17.5}$B$\text{}_{5}$. Magnetic hardening of the alloys at the onset of crystallization was studied by the two independent techniques, i.e. measurements of the magnetization hysteresis loops and Barkhausen effect. A good correlation between the coercivity and the maximum power of the Barkhausen noise has been found in these two compositions of the alloys.
    Źródło:
    Acta Physica Polonica A; 1997, 91, 2; 435-438
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Phase Transitions in ErFe$\text{}_{1-x}$Al$\text{}_{x}$O$\text{}_{3}$ System (x ≤ 0.1)
    Autorzy:
    Bombik, A.
    Pacyna, A. W.
    Witek, W.
    Powiązania:
    https://bibliotekanauki.pl/articles/1929847.pdf
    Data publikacji:
    1994-02
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.30.Gw
    75.60.–d
    Opis:
    The magnetic measurements for some representatives of ErFe$\text{}_{1-x}$Al$\text{}_{x}$O$\text{}_{3}$ system were performed. The obtained results indicate an essential influence of nonmagnetic substitution on physical behaviour of examined compounds.
    Źródło:
    Acta Physica Polonica A; 1994, 85, 2; 263-266
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    On Magnetization Reversal in Hard Magnetic Sm-Fe-N Permanent Magnets
    Autorzy:
    Pawlik, P.
    Wysłocki, J. J.
    Baran, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/2029275.pdf
    Data publikacji:
    2001-12
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.50.-y
    75.60.-d
    Opis:
    The investigations were carried out on Sm-Fe-N permanent magnets produced by reactive diffusion method. The magnets consist of hard magnetic phases: Sm$\text{}_{2}$Fe$\text{}_{17}$N$\text{}_{0.86}$ and SmFe$\text{}_{5}$ and soft magneticα-Fe phase. From the comparison of experimentally determined angular dependence of coercive field with appropriate theoretical predictions and from the dependence of coercive field on the external magnetic field determined from the minor hysteresis loops, it was stated that magnetization reversal process in Sm-Fe-N magnets is controlled by the nucleation of reversed domains process.
    Źródło:
    Acta Physica Polonica A; 2001, 100, 6; 905-913
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Effect of Fe substitution on structural and magnetic properties of NiCr₂O₄
    Autorzy:
    Mohanty, P.
    Prinsloo, A.
    Sheppard, C.
    Roos, W.
    Powiązania:
    https://bibliotekanauki.pl/articles/1048307.pdf
    Data publikacji:
    2018-03
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.50.Gg
    75.60.-d
    Opis:
    At room temperature, the normal oxide spinel NiCr₂O₄ is tetragonally distorted and crystallizes in the I4₁/amd space group due to cooperative Jahn-Teller ordering driven by the orbital degeneracy of tetrahedral Ni²⁺. The ferrimagnetic Curie temperature (T_{C}) for NiCr₂O₄ is 74 K. The magnetic moments of NiCr₂O₄ are composed of a ferrimagnetic (longitudinal) and an antiferromagnetic (transverse) component. Exchange interaction between the magnetic cations influences the overall magnetic properties of the compound. Present work focuses on the modification of structural and magnetic properties upon substituting Fe at Cr site in NiCr₂O₄ with the motivation of changing the magnetic exchange interaction. In order to do so, single phase Ni(Cr_{0.5}Fe_{0.5})₂O₄ samples were prepared by co-precipitation techniques, while controlling the pH of precipitation. Upon Fe substitution, crystal structure was not affected much contrary to the earlier reports. In order to determine the oxidation state of each elements X-ray photoelectron spectroscopy (XPS) was performed. T_{C} was found to increase dramatically above 300 K, confirmed both from temperature and field dependent dc-magnetization studies.
    Źródło:
    Acta Physica Polonica A; 2018, 133, 3; 574-577
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Investigation of Total Losses of Non-Oriented Electrical Steels
    Autorzy:
    Füzer, J.
    Birčáková, Z.
    Zeleňáková, A.
    Hrubovčák, P.
    Kollár, P.
    Predmerský, M.
    Huňady, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/1535263.pdf
    Data publikacji:
    2010-11
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.50.Bb
    75.60.-d
    Opis:
    The aim of this work was to investigate the influence of microstructural features on the soft magnetic properties. The materials chosen for this work were two types of the Epstein strips of commercially produced non-oriented electrical steels by U.S. Steel Košice. The AC magnetic properties in 0.2-100 Hz frequency range were obtained by measurements of AC hysteresis loops by a fluxmeter based non-standard single sheet AC hysteresisgraph. The influence of the grain size and magnetic domains structure on the partial contributions (hysteresis, eddy current and anomalous) to the total losses is also discussed. The results of the frequency dependence of the total losses, measured by a single sheet loop tracer along the rolling direction and perpendicular to the rolling direction, show different contribution of partial components.
    Źródło:
    Acta Physica Polonica A; 2010, 118, 5; 1018-1019
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The Rare-earth Based Single-ion Magnet $CsNd(MoO_{4})_{2}$
    Autorzy:
    Tkáč, V.
    Tibenská, K.
    Orendáčová, A.
    Orendáč, M.
    Anders, A.
    Pavlík, V.
    Feher, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/1368610.pdf
    Data publikacji:
    2014-07
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.40.-s
    75.60.-d
    Opis:
    Specific heat, magnetization and DC susceptibility of the single crystal $CsNd(MoO_{4})_{2}$,a layered rare-earth dimolybdate, have been investigated nominally, in the temperature range from 100 mK to 300 K in the magnetic field up to 5 T, applied along the a axis. The analysis of the experimental data revealed the absence of a phase transition to the magnetic ordered state down to 100 mK. The application of a standard two-level model yielded an excellent agreement with the specific heat data above 2 K in nonzero magnetic field indicating a weakness of magnetic correlations and a predominant occupation of the ground-energy doublet. The latter indicates a large energy separation between the ground and first excited doublet. These measurements suggest that $CsNd(MoO_{4})_{2}$ can represent a good realization of a single-ion magnet.
    Źródło:
    Acta Physica Polonica A; 2014, 126, 1; 244-245
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Magnetization Study of the AFM-FM Coexistence in the Manganite System $Pr_{0.5}Ca_{0.5-x}Sr_xMnO_3$
    Autorzy:
    Maryško, M.
    Jirák, Z.
    Powiązania:
    https://bibliotekanauki.pl/articles/1813589.pdf
    Data publikacji:
    2008-01
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.60.-d
    75.47.Lx
    Opis:
    For the manganites $Pr_{0.5}Ca_{0.5-x}Sr_xMnO_3$ (x=0;0.3) the temperature and cooling field dependence of the reduced remanence asymmetry indicates the antiferromagnetic exchange between the antiferromagnetic and ferromagnetic spins at the surface of the clusters. For x=0.3 we deduce the radius of the cluster in the field cooled regime to be about 20 times larger than that for x=0.
    Źródło:
    Acta Physica Polonica A; 2008, 113, 1; 143-146
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Magnetic Tailoring of Domains in NiFe/Au/Co/Au Multilayers by He Ion Bombardment through Nanospheres
    Autorzy:
    Glapka, W.
    Kuświk, P.
    Sveklo, I.
    Urbaniak, M.
    Jóźwiak, K.
    Weis, T.
    Engel, D.
    Ehresmann, A.
    Błaszyk, M.
    Szymański, B.
    Maziewski, A.
    Stobiecki, F.
    Powiązania:
    https://bibliotekanauki.pl/articles/1810578.pdf
    Data publikacji:
    2009-01
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.70.-i
    75.60.-d
    Opis:
    Sputter deposited $(Ni_{80}Fe_{20}//Au//Co//Au)_{10}$ multilayers, characterized by alternating in-plane and perpendicular anisotropies of the NiFe and Co layers, respectively, and out-of-plane stripe (labyrinth) domain structure in the Co layers, were bombarded by $He^+$-ions (10 keV) through a mask consisting of polystyrene nanospheres with a diameter of 470 nm. The changes of multilayers magnetic properties after ion bombardment are correlated with the used mask structure.
    Źródło:
    Acta Physica Polonica A; 2009, 115, 1; 348-351
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Separation of Magnetization Loop in Domain Wall Movement and Domain Rotation Contributions for Soft Magnetic Materials
    Autorzy:
    Varga, L.
    Kovács, Gy.
    Powiązania:
    https://bibliotekanauki.pl/articles/1813593.pdf
    Data publikacji:
    2008-01
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.50.Bb
    75.60.-d
    Opis:
    The domain wall movement and magnetization rotations processes are separated experimentally in quasi-static magnetization process of a Finemet type ultrasoft magnetic material. The reversible domain rotations contribution is obtained from the integration of the reversible permeability, $μ_{DR}$, as a function of biasing DC field, measured with very small alternative field amplitude, less than 0.05 $H_c$. The domain wall movement component is obtained by the integration of the permeability obtained by extraction of $μ_{DR}$ from the differential permeability derived from one branch of the quasi-static major loop.
    Źródło:
    Acta Physica Polonica A; 2008, 113, 1; 159-162
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Mechanism of Rotational Hysteresis Energy in Sm-Fe-N Permanent Magnets
    Autorzy:
    Pawlik, P.
    Wysłocki, J. J.
    Dziliński, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/2030425.pdf
    Data publikacji:
    2002-02
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.30.-m
    75.60.-d
    Opis:
    Investigations were carried out on Sm-Fe-N permanent magnet produced by the reactive diffusion method with different grain sizes (from 8.6 to 0.97μm). The rotational hysteresis energy has been measured as a function of the applied field. The proposed model of rotational hysteresis energy is in good agreement with the experimental results. It is shown that the magnetization reversal process in Sm-Fe-N magnet is controlled by the nucleation of reversed domains.
    Źródło:
    Acta Physica Polonica A; 2002, 101, 2; 267-277
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Investigation of Magnetization Processes from the Energy Losses in Soft Magnetic Composite Materials
    Autorzy:
    Birčáková, Z.
    Kollár, P.
    Weidenfeller, B.
    Füzer, J.
    Fáberová, M.
    Bureš, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/1032811.pdf
    Data publikacji:
    2017-04
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.50.Bb
    75.60.Jk
    75.60.-d
    Opis:
    Soft magnetic composite materials are composed of small ferromagnetic particles insulated from each other. It gives them some very good properties e.g. the magnetic isotropy and low total energy losses at medium to higher frequencies. On the other hand, their structure gives rise to the negative aspects as the inner demagnetizing fields, resulting in some specifics in magnetization processes leading to the worsening of soft magnetic properties, particularly the excess losses increase and a lowering of permeability. The frequency dependence of excess losses, the low and high induction loss components and the inner demagnetization factors of soft magnetic composites were investigated in order to reveal the proportions of the reversible and irreversible magnetization processes. Higher excess losses were observed in samples with smaller particles or higher non-ferromagnetic content (resin+pores), in which the inner demagnetizing fields were higher. It was explained by lower effective number of movable domain walls in those samples, thus less irreversible magnetization processes. This was confirmed by low and high induction loss analysis, where total losses were divided into low and high induction loss components and plotted vs. frequency.
    Źródło:
    Acta Physica Polonica A; 2017, 131, 4; 684-686
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    DC Magnetic Properties and Complex Permeability of Ni-Fe Based Composites
    Autorzy:
    Onderko, F.
    Jakubčin, M.
    Dobák, S.
    Olekšáková, D.
    Birčáková, Z.
    Kollár, P.
    Füzer, J.
    Fáberová, M.
    Bureš, R.
    Kurek, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/1032820.pdf
    Data publikacji:
    2017-04
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.50.Bb
    75.60.Jk
    75.60.-d
    Opis:
    We have investigated soft magnetic composite materials to better understand the influence of binder (resin) content on the DC magnetic properties and the complex permeability. Soft magnetic composite samples were composed from NiFe powder with phenol formaldehyde resin (ATM). Ferromagnetic magnetic powder for ring-shaped samples was obtained by milling of small pieces cut of NiFe sheets. The obtained powder was annealed to partially remove structural defects. The prepared powder was mixed with phenol-formaldehyde resin in different vol.%. The mixtures were pressed into the ring-shape samples. Complex permeability and DC magnetic properties (initial magnetization curves, anhysteretic curves and hysteresis loops) were measured. Higher inner demagnetizing fields in the resin containing samples were responsible for higher coercivity and hysteresis losses, but the permeability was stable up to much higher frequencies, compared to the sample without the resin.
    Źródło:
    Acta Physica Polonica A; 2017, 131, 4; 792-794
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Influence of Vitroperm Content on the Energy Losses in Composite Materials Based on the Mixture of Two Ferromagnets
    Autorzy:
    Birčáková, Z.
    Kollár, P.
    Vojtek, V.
    Bureš, R.
    Fáberová, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/1200792.pdf
    Data publikacji:
    2014-07
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.50.Bb
    75.60.Jk
    75.60.-d
    Opis:
    Soft magnetic composites offer several advantages such as 3D isotropic magnetic properties and relatively small energy losses, finding use in electrical devices like electromotors, transformers or sensors. The aim of this work was to investigate the dc and ac magnetic properties of composites based on the mixture of two different ferromagnets: iron based material Somaloy® 700 and Vitroperm® 500 alloy. The analysis of total losses into dc losses, classical losses and excess losses showed that the classical and excess losses were negligibly small. The specific resistivity was increasing with the increasing fraction of Vitroperm (VPM). The coercivity exhibited maximum at 20% of VPM.
    Źródło:
    Acta Physica Polonica A; 2014, 126, 1; 114-115
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Scaling of anhysteretic curves for LaFeCoSi alloy near the transition point
    Autorzy:
    Gozdur, R.
    Chwastek, K.
    Najgebauer, M.
    Lebioda, M.
    Bernacki, Ł.
    Wodzyński, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/1053125.pdf
    Data publikacji:
    2017-04
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.30.Sg
    75.60.-d
    75.60.Ej
    Opis:
    LaFeCoSi alloys have attracted much attention as they exhibit magnetocaloric effect in near room temperature. The paper focuses on the description of anhysteretic curve for LaFeCoSi alloy for temperatures close to transition point. For this purpose the Langevin function is applied. The paper confirms that the Langevin function might be a good starting point for development of analytical models aimed at examination of magnetic properties in La-based magnetocaloric materials.
    Źródło:
    Acta Physica Polonica A; 2017, 131, 4; 801-803
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Hysteresis Effect in Mean-Field Model
    Autorzy:
    Pełka, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/1199505.pdf
    Data publikacji:
    2014-07
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.60.-d
    75.50.Vv
    75.60.Ej
    Opis:
    A simple feedback loop and a mean-field approximation are employed to simulate the memory effect in the exchange-coupled magnetic system. The nonlinearity of the feedback turns out to be the crucial factor for the appearance of hysteresis loops. A threshold value above which the hysteresis disappears is the mean-field transition temperature. Temperature dependence of the coercive field is investigated.
    Źródło:
    Acta Physica Polonica A; 2014, 126, 1; 28-29
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Coercivity of Ultrathin Magnetic Films with Perpendicular Anisotropy
    Autorzy:
    Zablotskii, V.
    Kisielewski, M.
    Tsiganenko, O.
    Ferre, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/2013072.pdf
    Data publikacji:
    2000-03
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.60.-d
    75.60.Ch
    75.70.Ak
    Opis:
    The calculation of the temperature dependence of the domain wall coercivity of ultrathin magnetic films with perpendicular anisotropy is reported. In this case, the magnetization reversal is supposed to occur through domain wall motion. The proposed model takes into account thermal bending fluctuations of the domain wall, which is pinned by crystal defects such as grain boundaries. A fitting procedure, applied to recently published experimental data on the field induced domain wall velocity in Au/Co films, allows us to find out realistic values of the involved parameters.
    Źródło:
    Acta Physica Polonica A; 2000, 97, 3; 471-474
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Magnetic Fluxgate Sensor Characteristics Modeling Using Extended Preisach Model
    Autorzy:
    Frydrych, P.
    Szewczyk, R.
    Salach, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/1199497.pdf
    Data publikacji:
    2014-07
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.60.-d
    07.07.Df
    Opis:
    This paper presents the implementation of the extended Preisach model for fluxgate sensor characteristics modeling. The developed model enables the optimization of fluxgate sensor parameters for a given core material. Model consists of two parts. The first one describes magnetic characteristics of the core, while the second part calculates output signal according to sensor dimensions and electric circuit parameters. The model is easy to adapt for modeling of other devices with magnetic cores. It can be used instead of costly and time consuming prototype testing.
    Źródło:
    Acta Physica Polonica A; 2014, 126, 1; 18-19
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    On Temperature Dependence of Domain Structure in Cobalt
    Autorzy:
    Szmaja, W.
    Polański, K.
    Dolecki, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/1964829.pdf
    Data publikacji:
    1997-08
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.60.-d
    64.70.-p
    Opis:
    The type-I magnetic contrast in a scanning electron microscope is used to study the domain behaviour on the basal planes of cobalt monocrystals of different thicknesses during a heating cycle. Digital image processing is applied to the original scanning electron microscope images for their restoration, enhancement and analysis. The main reasons for the application of digital image processing are: low level of type-I magnetic contrast, particularly used at the higher temperatures, and the complex character of the magnetic domain structure. The changes in both domain structures and type-I magnetic contrast are due to the strong temperature dependence of magnetocrystalline anisotropy energy for the hcp phase of cobalt, which implies the rotation of magnetic easy axis from the c-axis to the basal plane. The temperature of the magnetic phase transition between an open-flux and a closed-flux domain configuration was found to be dependent on the specimen thickness. The changes in domain structure during the heating cycle were reversible under the condition that the specimen was not carried through the hcp-to-fcc phase transition. Otherwise, they were partially or completely irreversible and were caused by crystal imperfections originating from the transition. The paper shows the great advantage of using digital image processing system for data restoration, enhancement and analysis.
    Źródło:
    Acta Physica Polonica A; 1997, 92, 2; 469-472
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The Effect of Residual Stresses on the Coercive Field Strength of Drawn Wires
    Autorzy:
    Suliga, M.
    Kruzel, R.
    Chwastek, K.
    Jakubas, A.
    Pawlik, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/1030254.pdf
    Data publikacji:
    2017-04
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    61.72.Hh
    75.60.-d
    75.60.Ej
    Opis:
    Residual stresses occurring in drawn wires due to technological process affect their quality, which in turn may have a substantial impact on safety of use and "life" of ready-made products. Measurements of magnetic properties of the wires like coercive field strength may be useful for monitoring the level of residual stresses. The present paper examines the relationship between the drawing speed and the coercive field strength in high carbon wires. It has been found that for drawing speeds not exceeding 20 m/s the coercive field strength is proportional to residual stresses on wire surface.
    Źródło:
    Acta Physica Polonica A; 2017, 131, 4; 1114-1116
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Application of Extended Jiles-Atherton Model for Modelling the Influence of Stresses on Magnetic Characteristics of the Construction Steel
    Autorzy:
    Jackiewicz, D.
    Szewczyk, R.
    Salach, J.
    Bieńkowski, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/1202331.pdf
    Data publikacji:
    2014-07
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.60.Ej
    75.60.-d
    81.70.-q
    Opis:
    Paper presents the possibility of application of the Jiles-Atherton extended model to describe the magnetic characteristics of construction steel C45 under the influence of tensile stresses. Experiment was performed on the frame-shaped samples. Then, the influence of stresses on hysteresis loops was modelled with the Jiles-Atherton extended model. The obtained results of the modelling are consistent with results of the experimental measurements. The results of modelling create new possibilities of explanation of the physical phenomena connected with magnetisation of the magnetic materials under stresses, which is esential for the assessment of the state of the construction steel during its exploitation in industrial conditions.
    Źródło:
    Acta Physica Polonica A; 2014, 126, 1; 392-393
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Minor Loops in the Harrison Model
    Autorzy:
    Chwastek, K.
    Szczygłowski, J.
    Wilczyński, W.
    Powiązania:
    https://bibliotekanauki.pl/articles/1431773.pdf
    Data publikacji:
    2012-04
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.60.-d
    75.60.Ej
    85.70.Ay
    Opis:
    A novel description of hysteresis phenomenon is presented. The examined description emphasizes the roles of bistability and quantum phenomena as processes responsible for hysteresis loop formation in magnetic materials. Major and symmetric minor hysteresis loops are modelled in chosen soft magnetic materials using the Harrison model. A reasonable agreement between theory and experiment is achieved.
    Źródło:
    Acta Physica Polonica A; 2012, 121, 4; 941-944
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Magnetic Properties of SMC Cores Produced at a Low Compacting Temperature
    Autorzy:
    Jakubas, A.
    Gębara, P.
    Seme, S.
    Gnatowski, A.
    Chwastek, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/1032892.pdf
    Data publikacji:
    2017-05
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.60.-d
    75.60.Ej
    77.84.Lf
    Opis:
    Soft magnetic composites are readily used in the design of electromagnetic converters and electrical machines. In the paper, the magnetic properties of "home-made" cores made of iron powder and suspense polyvinyl chloride are examined. Samples were prepared by hot pressing of a PVC/Fe powder mixture with a different ratio of constituent components. Phase composition was investigated using an X-ray diffractometer and the presence of α-Fe was detected. Measurements of magnetic permeability revealed its allometric decrease with an increase of PVC content in composite. For the description of magnetization curves the phenomenological Jiles-Atherton model is used. The results of simulations are in a qualitative agreement with experiment.
    Źródło:
    Acta Physica Polonica A; 2017, 131, 5; 1289-1293
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Nanocrystalline Permanent Magnets with Enhanced Properties
    Autorzy:
    Leonowicz, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/2035448.pdf
    Data publikacji:
    2002-07
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.50.-y
    75.60.-d
    75.75.+a
    Opis:
    Parameters of permanent magnets result from the combination of intrinsic properties such as saturation magnetization, magnetic exchange, and magnetocrystalline energy, as well as microstructural parameters such as phase structure, grain size, and orientation. Reduction of the grain size into nanocrystalline regime (≈50 nm) leads to the enhanced remanence which derives from ferromagnetic exchange coupling between highly refined grains. In this study the fundamental phenomena, quantities, and structure parameters, which define nanophase permanent magnets are presented and discussed. The theoretical considerations are confronted with experimental data for nanocrystalline Sm-Fe-N type permanent magnets.
    Źródło:
    Acta Physica Polonica A; 2002, 102, 1; 35-43
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Accents in Modern High Saturation Nanocrystalline Fe-Rich Alloys
    Autorzy:
    Butvinová, B.
    Butvin, P.
    Maťko, I.
    Janičkovič, D.
    Kuzminski, M.
    Ślawska-Waniewska, A.
    Švec, P.
    Chromčíková, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/1030276.pdf
    Data publikacji:
    2017-04
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.50.Bb
    75.60.-d
    75.75.-c
    Opis:
    Post processing limits for iron-rich Fe-Cu-Si-B-P high-induction rapidly-quenched ribbons have been tested. 530°C/20 min is already too much, formed borides being the essential culprit of magnetic properties deterioration. Unlike standard Si-poor Fe-Nb-Cu-B-Si Finemets, these alloys annealed even in "technical" Ar below the upper limit do not create significant squeezing surfaces.
    Źródło:
    Acta Physica Polonica A; 2017, 131, 4; 711-713
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Modeling the Hysteresis Loop in Hard Magnetic Materials Using T(x) Model
    Autorzy:
    Dośpiał, M.
    Nabiałek, M.
    Szota, M.
    Pietrusiewicz, P.
    Gruszka, K.
    Błoch, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/1201094.pdf
    Data publikacji:
    2014-07
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.60.-d
    75.60.Jk
    75.50.Vv
    75.60.Ej
    Opis:
    Possibility of decomposing the static hysteresis loop is demonstrated. The applied method is related with decomposition of experimentally obtained reversal magnetization curve on the reversible and irreversible components. Results are applicable in analysis of reversal magnetization processes in hard magnetic materials and for simulation of hysteresis loop using hyperbolic T(x) model.
    Źródło:
    Acta Physica Polonica A; 2014, 126, 1; 170-171
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Domains Stimulated Magnetostatic Coupling in NiFe/Au/Co/Au Multilayers Investigated by Complementary Methods
    Autorzy:
    Stobiecki, F.
    Urbaniak, M.
    Szymański, B.
    Kuświk, P.
    Schmidt, M.
    Aleksiejew, J.
    Weis, T.
    Engel, D.
    Lengemann, D.
    Ehresmann, A.
    Kopcewicz, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/1810577.pdf
    Data publikacji:
    2009-01
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.70.-i
    75.30.Gw
    75.60.-d
    Opis:
    The magnetic structure of $Ni_{80}Fe_{20}$/Au/Co/Au multilayers characterized by easy-plane and easy-axis perpendicular to the sample plane anisotropies for NiFe and Co, respectively, is strongly modified by magnetostatic coupling resulting from stray fields of stripe domains in the Co layers. Using complementary methods it will be shown that the magnetostatic coupling increases with decreasing Au spacer thickness, with the weakening of the easy plane anisotropy of the NiFe layers and with increasing thickness of the Co layers.
    Źródło:
    Acta Physica Polonica A; 2009, 115, 1; 345-347
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Thermomagnetic Properties and First-Order Reversal Curve Analysis of Annealed Fe-Co-Si-B-Mo-P Alloy
    Autorzy:
    Hasiak, M.
    Miglierini, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/1030239.pdf
    Data publikacji:
    2017-05
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.50.Bb
    75.60.-d
    75.50.Tt
    Opis:
    The paper presents thermomagnetic features and characterization of magnetic interactions in the Fe₅₁Co₁₂Si₁₆B₈Mo₅P₈ metallic glass after annealing at 798 K for 1 h. The first-order reversal curve analysis was used to investigate hysteresis curves which provide a more precise estimation of the strength of interactions. The presence of magnetically distinct regions was revealed.
    Źródło:
    Acta Physica Polonica A; 2017, 131, 5; 1222-1224
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Substitution effects on the magnetic properties of Fe-containing chalcogenides with NiAs-type structures
    Autorzy:
    Baranov, N.
    Selezneva, N.
    Sherokalova, E.
    Gubkin, A.
    Sherstobitov, A.
    Shishkin, D.
    Powiązania:
    https://bibliotekanauki.pl/articles/1050741.pdf
    Data publikacji:
    2018-03
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.30.Kz
    75.50.Vv
    75.60.-d
    Opis:
    The changes in the magnetization processes caused by Se for S substitutions in the layered chalcogenide compounds Fe_{x}TiS_{2-y}Se_{y} (x=0.5, 0.66) with antiferromagnetic (AF) and ferrimagnetic (FI) orderings, respectively, have been studied by using the magnetization and magnetoresistance measurements. Unusually high values of the coercive fields (H_{c} up to 56 kOe) have been observed at low temperatures in Fe_{0.5}TiS_{2-y}Se_{y} with the Se content y<0.5, which is ascribed to the presence of an unquenched orbital moment on Fe ions and to the formation of a magnetically heterogeneous state in the vicinity of H_{c}. The Se for S substitution in Fe_{0.66}TiS_{2-y}Se_{y} leads to the transition from the FI to AF state and to non-monotonous change of H_{c} with a maximal value 22 kOe an y=0.5. The changes in the magnetic state of Fe_{x}TiS_{2-y}Se_{y} are suggested to be strongly affected by the distribution of Fe ions and vacancies in cationic layers.
    Źródło:
    Acta Physica Polonica A; 2018, 133, 3; 447-449
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Evidence of Formation of $Co_{x}Cu_{1-x}$ Nanoparticles with Core-Shell Structure
    Autorzy:
    Dhara, S.
    Chowdhury, R.
    Bandyopadhyay, B.
    Powiązania:
    https://bibliotekanauki.pl/articles/1402071.pdf
    Data publikacji:
    2015-10
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.75.Fk
    61.05.cp
    75.60.-d
    Opis:
    We have prepared $Co_{x}Cu_{1-x}$ granular alloys with Co contents (x ≈ 0.01-0.30) by chemical reduction. Samples are characterized by X-ray diffraction and transmission electron microscopy yielding particles of mean diameter 8-20 nm formed in fcc phase. The branching in ZFC/FC magnetization behavior confirm superparamagnetism in the samples, characterized by blocking temperature distributions which represent variations in particle size and inhomogeneities of their chemical compositions. Magnetic field dependence of magnetization show hysteresis loops, and the magnetization at any temperature 4-300 K is a combination of ferromagnetism and superparamagnetism. The saturation moment of Co for the ferromagnetism part increases with the Co content. But the coercive fields $(H_{C})$ and magnetic anisotropy of the particles do not vary with Co concentration. Annealed samples exhibit exchange bias in the range 20-150 Oe at 4 K. The results indicate formation of nanoparticles of CoCu alloy in a core-shell type structure with Co being concentrated near the core.
    Źródło:
    Acta Physica Polonica A; 2015, 128, 4; 533-535
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    An Approach to Modeling and Scaling of Hysteresis in Magnetic Materials. Magnetization Curve
    Autorzy:
    Sokalski, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/1399336.pdf
    Data publikacji:
    2015-03
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.50.-y
    75.60.-d
    89.75.Da
    Opis:
    A new mathematical model of hysteresis loop has been derived. Model consists in an extension of tanh(·) by extending the base of exp function into an arbitrary positive number. The presented model is self-similar and invariant with respect to scaling. Scaling of magnetic hysteresis loop has been done using the notion of homogeneous function in general sense.
    Źródło:
    Acta Physica Polonica A; 2015, 127, 3; 850-853
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Effect of Mechanochemical Treatment on Magnetic Properties of Nanodimensional Magnetite-Type Materials
    Autorzy:
    Cherkezova-Zheleva, Z.
    Zaharieva, K.
    Buchkov, K.
    Blagoev, B.
    Mitov, I.
    Powiązania:
    https://bibliotekanauki.pl/articles/1382568.pdf
    Data publikacji:
    2014-10
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.60.-d
    75.75.-c
    82.80.Ej
    Opis:
    The presented study compares magnetic properties of Ni-doped magnetites $Ni_{0.5}^{2+}Fe_{0.5}^{2+}Fe_{2}^{3+}O_{4}$ to magnetite $(Fe_3O_4)$ sample. Physicochemical properties of materials were registered by means of X-ray powder diffraction, Mössbauer spectroscopy, saturation magnetization and physical properties measurement systems. It was obtained that used preparation procedures lead to synthesis of single phase spinel materials with close nanodimensional size about 8-12 nm. Mechanochemically synthesized sample shows better magnetic properties as lower blocking temperature of superparamagnetic state and minimal coercivity in comparison to other studied materials.
    Źródło:
    Acta Physica Polonica A; 2014, 126, 4; 912-915
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Magnetic Properties of the $Bi_{0.65}La_{0.35}Fe_{0.5}Sc_{0.5}O_3$ Perovskite
    Autorzy:
    Fedorchenko, A.
    Fertman, E.
    Desnenko, V.
    Kotlyar, O.
    Čižmár, E.
    Shvartsman, V.
    Lupascu, D.
    Salamon, S.
    Wende, H.
    Salak, A.
    Khalyavin, D.
    Olekhnovich, N.
    Pushkarev, A.
    Radyush, Yu.
    Feher, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/1398308.pdf
    Data publikacji:
    2017-04
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.85.+t
    75.60.Ej
    75.60.-d
    75.50.Ee
    Opis:
    Magnetic properties of polycrystalline multiferroic $Bi_{0.65}La_{0.35}Fe_{0.5}Sc_{0.5}O_3$ synthesized under high-pressure (6 GPa) and high-temperature (1500 K) conditions were studied using a SQUID magnetometer technique. The temperature dependent static magnetic moment M was measured in both zero-field-cooled and field-cooled modes over the temperature range of 5-300 K in low magnetic field H=0.02 kOe. The field dependent magnetization M(H) was measured in magnetic fields up to 50 kOe at different temperatures up to 230 K after zero-field cooling procedure. A long-range magnetic ordering of the antiferromagnetic type with a weak ferromagnetic contribution takes place below $T_{N} ≈ 220 K$. Magnetic hysteresis loops taken below $T_{N}$ show a huge coercive field up to $H_{c}$ ≈10 kOe, while the magnetic moment does not saturate up to 50 kOe. A strong effect of magnetic field on the magnetic properties of the compound has been found. Below $T_{N}$ ≈220 K the derivatives of the initial magnetization curves demonstrate the existence of a temperature-dependent anomaly in fields of H=15÷25 kOe. The nature of the anomaly is unknown and requires additional study.
    Źródło:
    Acta Physica Polonica A; 2017, 131, 4; 1069-1071
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Minor Loop Scaling Rules for Finemet Type Soft Magnetic Cores
    Autorzy:
    Varga, L.
    Kováč, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/1367508.pdf
    Data publikacji:
    2014-07
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.50.Bb
    75.50.Kj
    75.60.-d
    75.60.Ej
    Opis:
    The validity of the Steinmetz law $(P=K B^{n})$ has been analyzed using the tanh model, by splitting the minor loops in three or two components, corresponding to different magnetization processes at different excitation levels. It is shown that the original Steinmetz law with the exponent n=1.6 is valid only at and above the coercive field, for intermediate and high induction values, where all the three magnetization processes are present. At small magnetization levels the exponent is about 3, much higher than the original proposed value.
    Źródło:
    Acta Physica Polonica A; 2014, 126, 1; 156-157
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Influence of Transition Metal Substitution on the Low-Field Magnetic Properties in the $Gd(Ni_{1-x}T_{x})₃$ (T = Fe, Co) Intermetallic Compounds
    Autorzy:
    Bajorek, A.
    Chełkowska, G.
    Powiązania:
    https://bibliotekanauki.pl/articles/1397023.pdf
    Data publikacji:
    2018-03
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    71.20.Eh
    75.30.Gw
    75.60.-d
    Opis:
    The low-field magnetic properties of polycrystalline $Gd(Ni_{1-x}T_{x})₃$ (T = Fe, Co) intermetallic compounds are presented. The whole system crystallizes in the rhombohedral PuNi₃ type of crystal structure. The composition dependence of the Curie temperature $T_{C}(x)$ is associated with the change in the number of 3d electrons. Moreover, the field cooled and zero field cooled (FC-ZFC) curves at low applied magnetic field are related to the anisotropy of T element. The saturation magnetic moment $M_S(x)$ upon doping was estimated based on the hysteresis loops M(H).
    Źródło:
    Acta Physica Polonica A; 2018, 133, 3; 470-472
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Magneto-History Effect in the $Tb_{x}Gd_{1-x}Ni_3$ Compounds
    Autorzy:
    Bajorek, A.
    Chełkowska, G.
    Chrobak, A.
    Kwiecień-Grudziecka, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/1427387.pdf
    Data publikacji:
    2012-05
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    71.20.Eh
    75.30.Gw
    75.60.-d
    Opis:
    The compounds $Tb_{x}Gd_{1-x}Ni_3$ with a $PuNi_3$-type structure have been obtained. The magnetic properties have been investigated by using SQUID magnetometer (Quantum Design MPMS, temperature from 1.9 K to 300 K and magnetic field up to 7 T). The partial replacement of Gd by Tb atoms is reflected in a decrease of the ordering temperature from 115 K (x = 0.0) to 81 K (x=1.0) as well as the increase of the saturation magnetic moment $M_{S}$ from 6.93 $μ_{B}$/f.u. (x=0.0) to 7.14 $μ_{B}$/f.u. (x=1.0). A large difference of M(T) curves has been noticed between the so-called field cooling-zero field cooling magnetization. The thermomagnetic curves are sensitive to the applied magnetic field and their origin can be understood as the domain-wall pinning effect and as the temperature dependence of coercivity.
    Źródło:
    Acta Physica Polonica A; 2012, 121, 5-6; 1136-1138
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Photo-Induced Relaxation of Magnetization in Molecular Magnet
    Autorzy:
    Zieliński, P.
    Tracz, P.
    Podgajny, R.
    Pełka, R.
    Bałanda, M.
    Wasiutyński, T.
    Sieklucka, B.
    Powiązania:
    https://bibliotekanauki.pl/articles/1814014.pdf
    Data publikacji:
    2007-12
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.50.Xx
    75.60.-d
    78.20.Ls
    Opis:
    The experimental study of photo-induced magnetization of hybrid molecular magnet containing cobalt(II) and tungsten(V) magnetic centers bridged by 4,4'-bpy and $CN^-$ is presented. The observed increase in magnetization rate is attributed to the defects due to inter-valence transfer between $Co^{II}W^V$↔ $Co^{III}W^{IV}$. The time evolution of magnetization is parameterized by the power law rather than exponential function.
    Źródło:
    Acta Physica Polonica A; 2007, 112, S; S-183-S-188
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Link between Magnetic and Dielectric Properties in Magnetite
    Autorzy:
    Švindrych, Z.
    Youssef, A.
    Janů, Z.
    Powiązania:
    https://bibliotekanauki.pl/articles/1534794.pdf
    Data publikacji:
    2010-11
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    71.30.+h
    75.60.-d
    75.85.+t
    Opis:
    We have measured temperature dependence of magnetic and dielectric properties in high quality stoichiometric single-crystals of magnetite $(Fe_3O_4)$. At low temperatures, below the Verwey transition, both ac susceptibility and ac permittivity reveal similar relaxation processes. We discuss these effects in connection with domain structure and variable range hopping mechanism of electrical conductivity.
    Źródło:
    Acta Physica Polonica A; 2010, 118, 5; 940-941
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Ellipsometric Selective Sensitivity to Magnetic Nanostructures
    Autorzy:
    Hamrlová, J.
    Postava, K.
    Životský, O.
    Hrabovský, D.
    Pištora, J.
    Švec, P.
    Janičkovič, D.
    Maziewski, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/1534105.pdf
    Data publikacji:
    2010-11
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    78.20.Ls
    75.50.Bb
    75.60.-d
    Opis:
    Recently, we have shown that the approach of depth sensitivity of magneto-optic ellipsometry can be generalized to selectivity from different materials in nanostructures. We use the condition number as the figure of merit to quantify the magneto-optic selectivity to two different magnetic contributions in magnetic nanostructure. The method is demonstrated on nanostructures containing magnetically hard Fe particles in surface layer of soft FeNbB amorphous ribbon. We separated both magnetic contributions from measurement of hysteresis loops using magneto-optic Kerr effect in longitudinal configuration. Magneto-optic selectivity is discussed and theoretical model on the basis of effective medium is compared with experimental data of longitudinal magneto-optic Kerr effect depending on angle of incidence.
    Źródło:
    Acta Physica Polonica A; 2010, 118, 5; 837-839
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Hard and Soft X-Ray Reflectivity Studies οf $(NiFe//Au//Co//Au)_{10}$ Magnetic Multilayers
    Autorzy:
    Szymański, B.
    Stobiecki, F.
    Weis, T.
    Engel, D.
    Urbaniak, M.
    Kuświk, P.
    Lengemann, D.
    Ehresmann, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/1810593.pdf
    Data publikacji:
    2009-01
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    61.05.cm
    75.60.-d
    75.70.-i
    Opis:
    We report on hard and soft X-ray reflectivity investigations of $(Ni_{80}Fe_{20} (2.2 nm)//Au(2.3 nm)//Co(0.8 nm)//Au(2.3 nm))_{10}$ multilayers. Specular reflectivity curves were measured with Cu $K_{α}$ radiation and circularly polarized synchrotron radiation tuned to Co $L_{3}$ and Ni $L_{3}$ absorption edges. Structural properties of the multilayers were determined from the hard X-ray reflectivity curve. Comparison of reflectivity curves taken at different photon energies shows: (i) small difference in peak positions in dependence of reflectivity versus scattering vector q, (ii) different shapes of satellite Bragg peaks, (iii) different ranges of q for appearance of the Kiessig fringes. Analysis of soft X-ray reflectivity curves taken as a function of magnetic field allows to determine magnetic properties of Co and NiFe layer specifically.
    Źródło:
    Acta Physica Polonica A; 2009, 115, 1; 366-368
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The influence of temperature on unidirectional effect in domain wall propagation
    Autorzy:
    Onufer, J.
    Ziman, J.
    Rezničák, M.
    Kardoš, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/1054815.pdf
    Data publikacji:
    2017-04
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.30.Gw
    75.50.Kj
    75.60.-d
    75.60.Ch
    75.60.Jk
    Opis:
    It has been reported recently that domain wall mobility in Fe-based amorphous glass-coated microwire can be significantly different in the cases when magnetization reversal caused by domain wall motion results in different orientation of magnetization. This behaviour has been called unidirectional effect. The effect of temperature on domain wall velocity vs. axial magnetic field dependences was studied for glass-coated Fe_{77.5}Si_{7.5}B_{15} microwire samples with strong unidirectional effect. Unidirectional effect was observed for the whole temperature interval from 100 K up to room temperature. Analysis of the results obtained indicates that the model of a solid domain wall does not explain the observed v(H) dependences. It seems very probable that besides standard damping mechanisms also changes in structure (shape) of the domain wall as a function of velocity (magnetic field) should be considered. Understanding of this mechanism could also provide interpretation of unidirectional effect.
    Źródło:
    Acta Physica Polonica A; 2017, 131, 4; 723-725
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Application of Anisotropic Vector Preisach Model for Bulk Materials
    Autorzy:
    Frydrych, P.
    Szewczyk, R.
    Nowicki, M.
    Charubin, T.
    Powiązania:
    https://bibliotekanauki.pl/articles/1032677.pdf
    Data publikacji:
    2017-04
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.60.-d
    75.60.Ch
    75.60.Nt
    75.30.Gw
    85.70.-w
    Opis:
    In this paper possibility of application two-dimensional vector Preisach model for bulk materials was investigated. Physical magnetization mechanisms in bulk cores and thin ribbons were analyzed. Model is based on collection of the Preisach planes which describe material state in different angles on rotation plane. Presented model exhibits good conformity with experimental data for bulk as well for ribbon shaped cores. Model includes anisotropy and describes not only mean magnetization vector, but also distribution of magnetic moments for different angles.
    Źródło:
    Acta Physica Polonica A; 2017, 131, 4; 618-620
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Influence of Vitrovac Content on Magnetic Properties in Composite Materials Based on the Mixture of Two Ferromagnets
    Autorzy:
    Hegedűs, L.
    Kollár, P.
    Füzer, J.
    Bureš, R.
    Fáberová, M.
    Kurek, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/1032700.pdf
    Data publikacji:
    2017-04
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.50.Bb
    75.50.Cc
    75.50.Kj
    75.60.-d
    Opis:
    Soft magnetic composite materials play an important role in nowadays industry, replacing the traditional materials such as electrical steels and soft ferrites, especially at medium and higher frequency applications. The material can be tailored for a specific application by changing the composition of the material and by adaptation of the fabrication process. The aim of this work was to investigate the morphology, phase composition and magnetic properties of soft magnetic composite materials with various magnetic content to minimize the total magnetic losses. The prepared sample series was based on the mixture of two different ferromagnets Vitrovac 6155 and Somaloy 700 without addition of insulating material. The samples were prepared by conventional powder metallurgy with particular fraction of Vitrovac in the form of a ring for magnetic measurements in AC fields and electric resistivity measurements. The samples with 5 wt% and 20 wt% fractions of Vitrovac exhibit lower values of total losses in comparison with Somaloy heat treated at 530°C.
    Źródło:
    Acta Physica Polonica A; 2017, 131, 4; 765-767
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Study of Magnetic Inhomogeneity on the Magnetoimpedance Effect of Soft Magnetic Alloys
    Autorzy:
    Mohseni, S.
    Tehranchi, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/1810616.pdf
    Data publikacji:
    2009-01
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.30.Gw
    75.50.Kj
    75.60.-d
    75.40.Mg
    Opis:
    There are various annealing techniques to influence the magnetic anisotropy of amorphous soft magnetic alloys, applicable for magnetic sensing elements. Laser irradiation of amorphous magnetic ribbons is a kind of annealing method to affect their magnetic moment orientations and consequently change their magnetic anisotropy and magnetoimpedance effect. In this paper, we have studied the role of magnetic anisotropy in the magnetoimpedance effect of laser annealed amorphous ribbons. In our theoretical study, we took into account the variations of magnetic anisotropy constants of local magnetic moments after annealing process. We showed that the flatten magnetoimpedance response which was observed in the experiments can be justified by averaging different local anisotropies induced by laser processing.
    Źródło:
    Acta Physica Polonica A; 2009, 115, 1; 406-408
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Magnetotransport through Nanoconstriction in Ferromagnetic Semiconductor (Ga,Mn)As
    Autorzy:
    Figielski, T.
    Wosiński, T.
    Pelya, O.
    Sadowski, J.
    Morawski, A.
    Mąkosa, A.
    Dobrowolski, W.
    Jagielski, J.
    Wróbel, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/2035752.pdf
    Data publikacji:
    2003-06
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    73.63.-b
    75.60.-d
    73.20.Fz
    Opis:
    We studied narrow (submicron) constrictions in the layers of ferromagnetic semiconductor (Ga,Mn)As. We have demonstrated a contribution of the quantum localization effects to the magnetoresistance of the constricted samples. We have also found a negative contribution of a domain wall trapped in the constriction to the resistance, due presumably to the erasing of the localization effects by the domain wall.
    Źródło:
    Acta Physica Polonica A; 2003, 103, 6; 525-531
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Domain Dynamics in Nonequilibrium Random-Field Ising Models
    Autorzy:
    Hrivňak, S.
    Žukovič, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/1199544.pdf
    Data publikacji:
    2014-07
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.10.Hk
    75.10.-b
    75.60.-d
    75.78.-n
    Opis:
    We employ Monte Carlo simulations in order to study dynamics of the magnetization and domain growth processes in the random-field Ising models with uniform and Gaussian random field distributions of varying strengths. Domain sizes are determined directly using the Hoshen-Kopelman algorithm. For either case, both the magnetization and the largest domain growth dynamics are found to follow the power law with generally different exponents, which exponentially decay with the random field strength. Moreover, for relatively small random fields the relaxation is confirmed to comply with different regimes at early and later times. No significant differences were found between the results for the uniform and Gaussian distributions, in accordance with the universality assumption.
    Źródło:
    Acta Physica Polonica A; 2014, 126, 1; 38-39
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Stress-Induced Changes in Closure Domain Structure Dynamics in Bistable Ferromagnetic Microwire
    Autorzy:
    Onufer, J.
    Ziman, J.
    Kladivová, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/1367053.pdf
    Data publikacji:
    2014-07
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.30.Gw
    75.50.Kj
    75.60.-d
    75.60.Ch
    75.60.Ej
    75.60.Jk
    Opis:
    A new experimental method for the study of closure domain structure dynamics in bistable ferromagnetic microwires is proposed. The simple experimental set-up enables detection of the presence of a free domain wall in the wire after application of a well-defined rectangular magnetic field pulse. The changes in closure domain structure dynamics, caused by applied tensile stress, are demonstrated by measurements on $Fe_{77.5}B_{15}Si_{7.5}$ glass-coated microwire. Minimum critical field for the release of a domain wall from the closure domain structure increases with increasing stress, while on the other hand, the minimum time needed for this process rapidly decreases with increasing stress.
    Źródło:
    Acta Physica Polonica A; 2014, 126, 1; 80-81
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Structural, 1/f Noise and MOKE Characterization of Vicinal La$\text{}_{0.7}$Sr$\text{}_{0.3}$MnO$\text{}_{3}$ Thin Films
    Autorzy:
    Méchin, L.
    Perna, P.
    Saïb, M.
    Belmeguenai, M.
    Flament, S.
    Barone, C.
    Routoure, J.-M.
    Simon, Ch.
    Powiązania:
    https://bibliotekanauki.pl/articles/2047216.pdf
    Data publikacji:
    2007-01
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.30.Gw
    75.47.Lx
    75.60.-d
    75.60.Jk
    75.70.Ak
    Opis:
    This paper presents some structural, magnetic and electrical properties of 40 nm and 75 nm thick La$\text{}_{0.7}$Sr$\text{}_{0.3}$MnO$\text{}_{3}$ thin films deposited on vicinal SrTiO$\text{}_{3}$(001) substrates. The vicinal angles were 2, 4, 6, 8, and 10º from the [001] direction towards [110]. Standard SrTiO$\text{}_{3}$(001) substrates were used for comparison and for the growth condition optimization. Structural properties were studied by X-ray diffraction, which indicated that the LSMO films grew with their (001) axis coincident with the (001) axis of the substrate. The surface morphology was carefully studied by atomic force microscopy in tapping mode. Very smooth films and regular step-terrace structures on the La$\text{}_{0.7}$Sr$\text{}_{0.3}$MnO$\text{}_{3}$ surfaces could be observed. The root mean square roughness measured in 2μ m×2μ m images was in the 0.130-0.580 nm range for all angles and both thicknesses. Superconducting quantum interference device magnetometer measurements revealed a Curie temperature in the 340-350 K range and magneto-optical Kerr microscopy enabled magnetic domain imaging and hysteresis loop measurements at 300 K. A uniaxial easy magnetization direction was obtained at 300 K for angles above 4º, with the easy axis along the steps. Finally, preliminary 1/f noise measurements were performed at 300 K for bias currents along and perpendicular to the step direction, showing a noise level as low as that we typically measured on standard SrTiO$\text{}_{3}$(001) substrates. All these results are promising for the future realization of room-temperature devices making use of the anisotropy of the magnetization.
    Źródło:
    Acta Physica Polonica A; 2007, 111, 1; 63-70
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Magnetic Properties of Yttrium-Substituted NiZn Ferrites
    Autorzy:
    Jančárik, V.
    Ušák, E.
    Šoka, M.
    Ušáková, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/1367108.pdf
    Data publikacji:
    2014-07
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.50.Gg
    75.30.Cr
    75.60.-d
    74.62.Dh
    Opis:
    Polycrystalline NiZn ferrite doped with a small amount of $Y^{3+}$ ions and having the composition of $Ni_{0.42}Zn_{0.58}Y_{x}Fe_{2-x}O_{4}$, where x=0.00, 0.01, 0.02, 0.04, 0.06, 0.08 and 0.10, was analyzed. Specimens were prepared by the ceramic method. Thermo-magnetic analysis and evaluation of hysteresis loops parameters were chosen as main examination methods in this study. Various parameters, such as Curie temperature $T_{C}$, coercive field $H_{c}$, remanent magnetic flux density $B_{r}$, hysteresis loop area and amplitude/initial permeability were studied at low frequencies.
    Źródło:
    Acta Physica Polonica A; 2014, 126, 1; 90-91
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Magnetization Processes of Nanoparticles Embedded into Ferromagnetic Matrix
    Autorzy:
    Ziółkowski, G.
    Chrobak, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/1387548.pdf
    Data publikacji:
    2015-02
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    81.07.Bc
    75.50.Tt
    75.60.-d
    75.78.Cd
    Opis:
    The paper refers to computer simulations of interactions between magnetically hard particle embedded into ultra-hard matrix. We used simulated annealing and Monte Carlo simulations in a frame of the 3D Heisenberg model. The performed simulations reveal that the particles show additional exchange anisotropy dependent on "frozen" spin direction in the matrix and the angle between matrix and particle easy magnetization axes. The particle-matrix coupling are responsible for multi-phase magnetic hysteresis shape and exchange-bias like effect.
    Źródło:
    Acta Physica Polonica A; 2015, 127, 2; 597-599
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Magneto-Optical Study of NiFe/Au/Co/Au Layers
    Autorzy:
    Mazalski, P.
    Postava, K.
    Tekielak, M.
    Maziewski, A.
    Urbaniak, M.
    Szymański, B.
    Stobiecki, F.
    Powiązania:
    https://bibliotekanauki.pl/articles/1810594.pdf
    Data publikacji:
    2009-01
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.60.-d
    75.70.-i
    75.70.Ak
    78.20.Ls
    Opis:
    Sputtered NiFe/Au/Co/Au layers with noncollinear magnetizations are of scientific interest for unusual magnetization behavior and their potential application in spintronics. In this paper, we propose to use a material selective sensitivity of magneto-optical Kerr effect for separation of signals from different materials in a bilayer system. The materials selective sensitivity is demonstrated on a sample with two mutually perpendicular Co and NiFe wedges.
    Źródło:
    Acta Physica Polonica A; 2009, 115, 1; 369-371
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Co_2FeSi Heusler Alloy Prepared by Arc Melting and Planar Flow Casting Methods: Microstructure and Magnetism
    Autorzy:
    Titov, A.
    Životský, O.
    Hendrych, A.
    Janičkovič, D.
    Buršík, J.
    Jirásková, Y.
    Powiązania:
    https://bibliotekanauki.pl/articles/1032650.pdf
    Data publikacji:
    2017-04
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    61.66.Dk
    75.50.Bb
    75.60.-d
    75.60.Ej
    75.70.Rf
    Opis:
    This paper is devoted to studies of the structural and magnetic properties of Co_2FeSi Heusler alloy produced by arc melting resulting in samples with large grains compared to finer-grained ribbon type samples prepared by planar flow casting. The scanning electron microscopy completed by energy dispersive X-ray spectroscopy, X-ray diffraction, and magnetic methods sensitive to both bulk and surface were applied. The chemical composition inside the grains was found to be in agreement with the nominal one while at the grain boundaries enrichment on Co and Si at expense of Fe was observed. The magnetic parameters derived from the bulk hysteresis curves resulted in nearly the same values of coercivity, about 1 kA/m, for both technological procedures while magnetization was of about 15 A m²/kg higher at ribbons compared with sample prepared by arc melting, 145 A m²/kg. The surface magnetic characteristics were visibly influenced by a surface magnetic anisotropy. The smooth polished surface of the sample prepared by arc melting has allowed visualizing the magnetic domain structure inside the grains and at grain boundaries by the magneto-optical Kerr microscopy and magnetic force microscopy.
    Źródło:
    Acta Physica Polonica A; 2017, 131, 4; 654-656
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Magnetic Properties of Crystalline NiFe Alloy Prepared by High-Energy Ball Milling and Compacting
    Autorzy:
    Olekšáková, D.
    Kollár, P.
    Füzer, J.
    Bednarčík, J.
    Roth, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/1533970.pdf
    Data publikacji:
    2010-11
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.50.Bb
    81.20.Wk
    75.50.Vv
    75.60.Ej
    75.60.-d
    Opis:
    The structure and magnetic properties of compacted microcrystalline NiFe (81 wt% of Ni) powder is investigated. The powder of NiFe alloy prepared by ball milling of ribbon (prepared by melt spinning) remains single phase material suitable for compaction in order to prepare soft magnetic material. The bulk samples were consolidated by uniaxial compaction of the powder in vacuum. By measuring of AC and DC magnetic properties it was found out that in bulk samples the displacement of domain walls is the dominant magnetization process, while rotation of magnetization vectors prevails in powder material.
    Źródło:
    Acta Physica Polonica A; 2010, 118, 5; 797-799
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The influence of NiZnFe₂O₄ content on magnetic properties of supermalloy type material
    Autorzy:
    Ďáková, L'.
    Füzer, J.
    Dobák, S.
    Kollár, P.
    Fáberová, M.
    Strečková, M.
    Bureš, R.
    Hadraba, H.
    Powiązania:
    https://bibliotekanauki.pl/articles/1053020.pdf
    Data publikacji:
    2017-04
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    07.55.-w
    75.60.-d
    75.50.Bb
    75.50.Gg
    Opis:
    Soft magnetic composites represent a remarkable kind of materials with wide variety of use. Magnetic properties are dependent on the materials composition and also on the method of preparation. Ni-Fe-Mo alloys (supermalloy) have high complex permeability and low eddy current losses. Soft magnetic NiZnFe₂O₄ ferrites have low coercivity and intermediate saturation magnetization. The Ni_{80}Fe_{14.7}Mo_{4.5}Mn_{0.5}Si_{0.3} (wt%) powder sample was prepared by mechanical alloying of the chemical elements for 24 h. Ni_{0.3}Zn_{0.7}Fe₂O₄ ferrite is commercially available by Sigma Aldrich. Both powders were mixed at selected ratio and uniaxially compacted at 800 MPa. In this paper, we report the experimental observations of the effects of Ni_{0.3}Zn_{0.7}Fe₂O₄ content on the electromagnetic properties of NiFeMoMnSi/Ni_{0.3}Zn_{0.7}Fe₂O₄. The samples contained 5, 10, and 15% of Ni_{0.3}Zn_{0.7}Fe₂O₄ ferrite and were sintered for 30 min at 800°C. An addition of Ni_{0.3}Zn_{0.7}Fe₂O₄ ferrite caused decrease of complex permeability and increase coercivity of the samples. The 5% of Ni_{0.3}Zn_{0.7}Fe₂O₄ sample exhibits the highest value of the real part of complex permeability (48 at 1 kHz). The 10% of Ni_{0.3}Zn_{0.7}Fe₂O₄ sample showed the lowest total magnetic losses.
    Źródło:
    Acta Physica Polonica A; 2017, 131, 4; 813-815
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Mössbauer Study of Magnetic Properties of $Fe_{80-x}Co_{x}Zr_7Si_{13}$ (x = 0-30~at.%) Boron-Free Amorphous Alloys
    Autorzy:
    Kopcewicz, M.
    Grabias, A.
    Latuch, J.
    Ferenc, J.
    Żuberek, R.
    Nesteruk, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/1428677.pdf
    Data publikacji:
    2012-05
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.50.Kj
    75.60.-d
    76.80.+y
    82.80.Ej
    Opis:
    Amorphous $Fe_{80-x}Co_{x}Zr_7Si_{13}$ (x = 0-30 at.%) alloys in which boron was completely replaced by silicon as a glass forming element have been prepared by melt quenching. Partial substitution of iron by cobalt caused the increase of the hyperfine field and saturation magnetization. The specialized rf-Mössbauer measurements revealed that all amorphous alloys studied are magnetically very soft. The rf-sidebands effect, related to magnetostriction, increases with the increase of Co content. In $Fe_{50}Co_{30}Zr_7Si_{13}$ sample the rf field exposure induced partial crystallization of amorphous phase that was attributed to mechanical deformations related to high frequency magnetostrictive vibrations induced by the rf field. The measurements of the hysteresis loop revealed that coercivity increases for higher Co content.
    Źródło:
    Acta Physica Polonica A; 2012, 121, 5-6; 1257-1260
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Wide Frequency Range AC Magnetic Properties of Fe-Based Composite Materials
    Autorzy:
    Kollár, P.
    Birčáková, Z.
    Füzer, J.
    Füzerová, J.
    Bureš, R.
    Fáberová, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/1507025.pdf
    Data publikacji:
    2010-11
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    81.05.Ni
    85.70.-w
    75.60.-d
    75.50.Bb
    Opis:
    The aim of this work was to analyze the influence of resin content on contribution of the hysteresis, eddy current and anomalous losses to the total losses in the frequency range from DC to 150 kHz. The samples of composite material were prepared in the form of the ring with outer diameter of 25 mm, inner diameter of 17 mm and height approximately 3 mm and in the form of cylinder with diameter of 25 mm and height approximately 3 mm by a compaction of mixture of iron powder ASC100.29 (90 vol.%) and commercial termoset resins. The DC hysteresis losses were obtained by the measurements of DC hysteresis loops and the total power losses in the frequency range 0.4 Hz-150 kHz from AC hysteresis loops, both at maximum induction 0.05, 0.1 and 0.2 T. The magnetic properties of the composite rings were compared with the properties of the material prepared from the powder supported by Höganäs AB Sweden. By analyzing the frequency dependence of total losses of the Fe-based SMC we found out that hysteresis losses contribute to the total losses as a majority component.
    Źródło:
    Acta Physica Polonica A; 2010, 118, 5; 759-761
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Phase Stability of $(Fe_{80}Nb_{6}B_{14})_{0.9}Tb_{0.1}$ Bulk Nanocrystalline Magnet
    Autorzy:
    Chrobak, A.
    Ziółkowski, G.
    Randrianantoandro, N.
    Powiązania:
    https://bibliotekanauki.pl/articles/1367802.pdf
    Data publikacji:
    2014-07
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    81.07.Bc
    75.50.Tt
    75.60.d
    76.80.+y
    Opis:
    The paper refers to phase stability of the $(Fe_{80}Nb_{6}B_{14})_{0.9}Tb_{0.1}$ bulk nanocrystalline alloys prepared using the vacuum suction casting technique. The samples were in the form of rods with diameters d=2, 1.5, 1 and 0.5 mm. Heating up to 900 K reveals structural changes that occur at temperatures above 680 K (DSC and M(T) measurements). The phase analysis, using Mössbauer spectra, indicates the decrease of $Tb_{2}Fe_{14}B$ and increase of Fe content in the samples after the heat treatment. The most stable is the alloy with d=1 mm, where the formation of α-Fe phase was not observed. The decrease of d causes significant hardening i.e. coercive field increases from 0.57 T to 2.66 T for d=2 mm and d=0.5 mm, respectively.
    Źródło:
    Acta Physica Polonica A; 2014, 126, 1; 176-177
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Influence of Cooling Rate on Magnetic Properties of $(Fe_{80}Nb_{6}B_{14})_{1-x}Tb_{x}$ Type of Bulk Nanocrystalline Alloys
    Autorzy:
    Chrobak, A.
    Ziółkowski, G.
    Haneczok, G.
    Powiązania:
    https://bibliotekanauki.pl/articles/1367856.pdf
    Data publikacji:
    2014-07
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    81.07.Bc
    75.50.Tt
    75.60.d
    76.80.+y
    Opis:
    The paper refers to magnetic properties of the $(Fe_{80}Nb_{6}B_{14})_{1-x}Tb_{x}$ (x=0.06 and x=0.08) bulk nanocrystalline alloys prepared using the vacuum suction casting technique. The samples were in the form of rods with diameters of d=1.5 mm, 1 mm and 0.5 mm. It was shown that for the alloys with x=0.08 the significant magnetic hardening with the decrease of sample diameter was observed. For d=0.5 mm the coercive field equals 2.46 T and the maximum energy product $|JH|_{max}$=77.2 kJ/$m^{3}$.
    Źródło:
    Acta Physica Polonica A; 2014, 126, 1; 178-179
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Spin-1 Model of Noninteracting Nanoparticles
    Autorzy:
    Yalçin, O.
    Erdem, R.
    Övűnç, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/1812046.pdf
    Data publikacji:
    2008-10
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.50.Tt
    75.60.-d
    05.50.+q
    05.70.Ln
    Opis:
    In this work, we presented a spin-1 model to investigate the magnetic properties of noninteracting monodomain nanoparticles based on the pair approximation. Nearest-neighbor pair interactions are incorporated between the Ising spins in three parts that are core, core-surface, and surface within the nanoparticle. Using the spin-1 Ising model of magnetization in the pair approximation, we calculated the free energy and minimized with respect to pair variables to obtain the field-cooled magnetization. Hysteresis loops of the system were plotted for various values of exchange coupling constants, and axial anisotropy of strength which couples the core, core-surface, and surface regions. The coercive field and its linear fit to the data were plotted as a function of radius of ferromagnetic nanoparticles.
    Źródło:
    Acta Physica Polonica A; 2008, 114, 4; 835-844
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Effects of Ru Addition on the Superconducting Properties of the Eu-123 System
    Autorzy:
    Škrátek, M.
    Cigáň, A.
    Dvurečenskij, A.
    Majerová, M.
    Bystrický, R.
    Billik, P.
    Maňka, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/1384837.pdf
    Data publikacji:
    2015-02
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    74.72.-h
    74.25.Ha
    75.30.Et
    75.60.-d
    Opis:
    Effects of the Ru addition on the structural and superconducting properties of the Eu-123 system were studied. Samples of the nominal composition $EuBa₂Cu_{3-x}Ru_{x}O_{7-δ}$ with x ranging from 0.0 to 0.7 were prepared by the solid state reaction technique from Eu₂O₃, BaCO₃, CuO and RuO₂ precursors at the temperature of 1050°C for 72 h in flowing oxygen and oxygen-annealed at 580°C for 24 h. X-ray diffraction data show the presence of another Ba-Eu-Ru-O phase, for x ≥ 0.03, in addition to the main superconducting phase. AC and DC magnetization characteristics were measured by the compensation method using the second-order SQUID gradiometer at ≈ 77 K and the QD SQUID magnetometer MPMS XL-7 at 20 K. The superconducting properties, $T_{c}$, $ΔT_{c}$, change only weakly up to x = 0.2, and magnetization M(H) deteriorates with an increasing Ru content.
    Źródło:
    Acta Physica Polonica A; 2015, 127, 2; 225-227
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Magnetic Studies of $EuBa₂Cu_{3-x}RuₓO_{7-δ}$ Compounds
    Autorzy:
    Dvurečenskij, A.
    Cigáň, A.
    Bystrický, R.
    Škrátek, M.
    Billik, P.
    Majerová, M.
    Maňka, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/1385423.pdf
    Data publikacji:
    2015-02
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    74.72.-h
    74.25.Ha
    75.30.Et
    75.60.-d
    Opis:
    Effects of Ru addition on magnetic properties of $EuBa₂Cu_{3-x}RuₓO_{7-δ}$ compounds were studied. Samples of $EuBa₂Cu_{3-x}RuₓO_{7-δ}$ with x from 0.00 to 0.70 were prepared by the solid state reaction technique from Eu₂O₃, BaCO₃, CuO and RuO₂ precursors. Temperature dependences of the zero-field cooled (ZFC) and the field cooled (FC) DC magnetic moment at low and high applied magnetic field Hₐ were measured by the QD SQUID magnetometer MPMS XL-7 and AC magnetization $M_{AC}(H)$ curves at 77 K by the compensation method using the second-order SQUID gradiometer. The molar susceptibility χ of the samples was corrected to the effects of the sample holder and diamagnetism and χ* also was corrected to the temperature independent paramagnetic/diamagnetic contribution $χ^{TN}$ and fitted by the Curie-Weiss relation. The values of the Weiss temperature and the effective magnetic moment have been estimated at low and high value of applied magnetic field.
    Źródło:
    Acta Physica Polonica A; 2015, 127, 2; 300-302
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Size Effect of Hard Magnetic Properties of Fe-Nb-B-Tb Milled Alloys
    Autorzy:
    Granek, K.
    Ziółkowski, G.
    Chrobak, A.
    Klimontko, J.
    Talik, E.
    Powiązania:
    https://bibliotekanauki.pl/articles/1030390.pdf
    Data publikacji:
    2018-03
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    81.07.Bc
    75.50.Tt
    75.60.d
    76.80.+y
    Opis:
    The paper refers to magnetic and structural properties of powders made of Fe-Nb-B-Tb ultra-high coercive alloy. The initial alloy was milled in a low energy mill for 1 h and 14 h. With increasing milling time we observed gradual deterioration of hard magnetic properties i.e. the coercive field decreases from 5.51 T to 0.14 T for the bulk alloy and 14 h milled powder, respectively. However, for the 1 h milling time the micrometric powder reveals quite high coercivity of 2.77 T which is promising for possible applications in magnetic composites.
    Źródło:
    Acta Physica Polonica A; 2018, 133, 3; 645-647
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Nanoscale Analysis of Superparamagnetic Systems
    Autorzy:
    Chrobak, A.
    Ziółkowski, G.
    Powiązania:
    https://bibliotekanauki.pl/articles/1033082.pdf
    Data publikacji:
    2017-05
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    81.07.Bc
    75.50.Tt
    75.60.-d
    76.80.+y
    Opis:
    The paper refers to a kind of nanoscale characterization of superparamagnetic materials above and below the so-called blocking temperature. It is propose to apply the Stoner-Wohlfarth model of nanoparticles magnetization supplemented by the two-level kinetic model, determining behavior in T>0. This approach allows determination of distribution of magnetic moments and energetic barriers of magnetic objects based on magnetization curves. In many cases, the determined distribution of magnetic moments can be recalculated into average size of the magnetic objects giving finally a nano/microscaled picture of the material. The proposed method was successfully used in characterization of diluted magnetics, nanocomposites, powders and even for human hemoglobin. In the paper the basic theory and its application to the nanoscale characterization is discussed in detail.
    Źródło:
    Acta Physica Polonica A; 2017, 131, 5; 1371-1374
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Optimization of soft magnetic properties in Fe₈₂Nb₂B₁₄RE₂ (RE = Y, Gd, Tb and Dy) group of amorphous alloys
    Autorzy:
    Chrobak, A.
    Haneczok, G.
    Zivotsky, O.
    Hendrych, A.
    Kansy, J.
    Kotur, B.
    Powiązania:
    https://bibliotekanauki.pl/articles/1113556.pdf
    Data publikacji:
    2016-10
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    81.07.Bc
    75.50.Tt
    75.60.-d
    76.80.+y
    Opis:
    Enhancement of soft magnetic properties in the selected group of amorphous alloys was examined by different experimental methods. It was shown that permeability for annealed samples (at T_{a} for 1 h; 300 K < T_{a} < 900 K) plotted vs. T_{a} shows a maximum at which is 700, 725, 725, and 750 K for Fe₈₂Nb₂B₁₄Y₂, Fe₈₂Nb₂B₁₄Gd₂, Fe₈₂Nb₂B₁₄Tb₂ and Fe₈₂Nb₂B₁₄Dy₂ alloy, respectively. For samples after the optimization annealing permeability is at least 10 times higher than in the as-quenched state. The optimized microstructure is free of iron nanograins and corresponds to so-called relaxed amorphous phase.
    Źródło:
    Acta Physica Polonica A; 2016, 130, 4; 916-919
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Influence of Transition and Rare Earth Elements on Magnetic Properties of Fe-Nb-B-M (M~=~Ni, Ag, Gd,~Tb) Bulk Nanocrystalline Alloys
    Autorzy:
    Ziółkowski, G.
    Randrianantoandro, N.
    Chrobak, A.
    Klimontko, J.
    Kądziołka-Gaweł, M.
    Haneczok, G.
    Powiązania:
    https://bibliotekanauki.pl/articles/1428970.pdf
    Data publikacji:
    2012-05
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    81.07.Bc
    75.50.Tt
    75.60.-d
    76.80.+y
    Opis:
    In this work we present magnetic properties of the $(Fe_{80}Nb_6B_{14})_{1-x}M_x$ (where M = Ni, Ag, Gd, Tb and x = 0.08, 0.16, 0.32) bulk nanocrystalline alloys prepared by making use of mould casting technique. The applied preparation technique is favorable to nanocrystallization of the alloys with mean diameters of crystallites ranged from about 10 nm to 30 nm. Phase identification reveals a formation of ternary $RE_2Fe_{14}B$ and binary $REFe_2$ phases dependently on the alloy composition. It was found that for the alloys with Ag addition magnetic moment of Fe atom increases from 2.26 $μ_{B}$ to 3.36 $μ_{B}$ for x = 0.08 and x = 0.32, respectively. For Ni addition this quantity decreases with increasing x due to appearing of Fe-Ni (fcc) phases. For Gd, Tb additions the alloys are ferrimagnetic with compensation composition ranged between x = 0.08 and x = 0.16. The both rare earth alloying additions cause a significant magnetic hardening especially in the case of Tb.
    Źródło:
    Acta Physica Polonica A; 2012, 121, 5-6; 1266-1269
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Magnetic Properties of Oxygen Deficient Y$\text{}_{0.33}$Sr$\text{}_{0.67}$CoO$\text{}_{3-δ}$
    Autorzy:
    Zhang, Y. F.
    Sasaki, S.
    Yanagisawa, O.
    Izumi, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/2047221.pdf
    Data publikacji:
    2007-01
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    72.80.Ga
    75.60.-d
    75.70.Rf
    81.40.Rs
    Opis:
    We studied magnetic properties of perovskite-type Y$\text{}_{0.33}$Sr$\text{}_{0.67}$ CoO$\text{}_{2.614}$ and Y$\text{}_{0.33}$Sr$\text{}_{0.67}$CoO$\text{}_{2.707}$ prepared under different sintered temperatures at 1250ºC and 1100ºC, respectively. A dc magnetization jump associated with a large thermal hysteresis around 180 K was found in Y$\text{}_{0.33}$Sr$\text{}_{0.67}$CoO$\text{}_{2.614}$, which indicates a kind of magnetic memory effect. On the other hand, Y$\text{}_{0.33}$Sr$\text{}_{0.67}$CoO$\text{}_{2.707}$ shows a larger magnetization with a small magnetization jump around 200 K and lower Curie temperature than those of Y$\text{}_{0.33}$Sr$\text{}_{0.67}$CoO$\text{}_{2.614}$. Rich Co$\text{}^{3+}$ ions in the low temperature sintered Y$\text{}_{0.33}$Sr$\text{}_{0.67}$CoO$\text{}_{2.707}$ possibly introduce large magnetization and high magnetization jump temperature. This may be coming from a surface/volume effect of Co$\text{}^{3+}$ ions appearing in the polycrystalline sample prepared at low temperature. The ferromagnetism resulted from the different surface/volume ratio contributes to a part of magnetization and may result in the change of the Curie temperature.
    Źródło:
    Acta Physica Polonica A; 2007, 111, 1; 79-86
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Characterization of Magnetosomes After Exposure to the Effect of the Sonication and Ultracentrifugation
    Autorzy:
    Molčan, M.
    Hashim, A.
    Kováč, J.
    Rajňák, M.
    Kopčanský, P.
    Makowski, M.
    Gojzewski, H.
    Molokáč, M.
    Hvizdák, L.
    Timko, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/1368025.pdf
    Data publikacji:
    2014-07
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    81.07.-b
    75.60.-d
    87.50.Y-
    68.37.-d
    Opis:
    Magnetosomes are intracellular organelles of widespread aquatic microorganisms called Magnetotactic bacteria. At present they are under investigation especially in biomedical applications. This ability depends on the presence of intracellular magnetosomes which are composed of two parts: first, nanometer-sized magnetite $(Fe_{3}O_{4})$ or greigite $(Fe_{3}S_{4})$ crystals (magnetosome crystal), depending on the bacterial species; and second, the bilayer membrane surrounding the crystal (magnetosome membrane). The magnetosomes were prepared by biomineralization process of magnetotactic bacteria Magnetospirillum Magnetotacticum sp. AMB-1. The isolated magnetosome chains (sample M) were centrifugated at speed of 100000 rpm for 4 hours (sample UM) and sonicated at power of 120 W for 3 hours (sample SM), respectively. The prepared suspensions were investigated with respect to morphological, structural and magnetic properties. The results from scanning electron microscopy showed that isolated chains of magnetosomes were partially broken to smaller ones after ultracentrifugation. On the other hand the application of the sonication process caused the formation of individual magnetosomes (unordered in chain). These results were confirmed by coercivity and magnetization saturation measurements.
    Źródło:
    Acta Physica Polonica A; 2014, 126, 1; 198-199
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Study on the Rayleigh Hysteresis Model and its Applicability in Modeling Magnetic Hysteresis Phenomenon in Ferromagnetic Materials
    Autorzy:
    Kachniarz, M.
    Szewczyk, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/1030243.pdf
    Data publikacji:
    2017-05
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.30.-m
    75.60.-d
    75.50.Gg
    75.50.Cc
    75.60.Ej
    07.05.Tp
    Opis:
    The following paper presents the basis of a Rayleigh magnetic hysteresis model and the examples of its application for modeling the magnetic characteristics of ferromagnetic materials: ferrites and steels. The presented model allows one to simulate the shape of a magnetic hysteresis loop of the material for the given value of the magnetizing field in the so-called Rayleigh region, as well as to calculate basic magnetic parameters of the material like coercive field, magnetic remanence, and power loss. Four different ferromagnetic materials (two ferrites and two alloy steels) were chosen for the investigation. Each material was investigated within the range of low magnetizing fields, corresponding to the Rayleigh region. On the basis of obtained results, modeling of magnetic characteristics of the investigated materials was performed. Moreover, the range of magnetizing field where the Rayleigh model can be applied for these materials was investigated based on correlation coefficient between experimental results and modeling.
    Źródło:
    Acta Physica Polonica A; 2017, 131, 5; 1244-1249
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Magnetic hardening induced in RCo₅ (R = Y, Gd, Sm) by short HEBM
    Autorzy:
    Łopadczak, P.
    Bajorek, A.
    Prusik, K.
    Zubko, M.
    Chełkowska, G.
    Powiązania:
    https://bibliotekanauki.pl/articles/1048324.pdf
    Data publikacji:
    2018-03
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    81.07.-b
    81.07.Bc
    75.50.Ww
    75.60.-d
    75.75.Cd
    Opis:
    The paper is focused on the magnetic and structural properties of RCo₅ (R = Y, Gd, Sm) intermetallics fabricated by high energy ball - milling (HEBM). The investigated samples were first produced by arc-melting as bulk materials and then were milled for 1h in dimethylformamide with balls to powder ratio 10:1. The influence of the HEBM parameters on the microstructure was investigated by a variety of complementary measurement methods. The Rietveld refinement was performed to estimate the dependence of crystallite size and microstrain on type of sample. The hysteresis loops were recorded by SQUID magnetometer at 2 K and 300 K and at magnetic field up to μ₀H=7 T. The impact of short HEBM process is visible as the enhancement of coercivity and simultaneous reduction of the saturation magnetization.
    Źródło:
    Acta Physica Polonica A; 2018, 133, 3; 688-690
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Single Domain Wall Contribution to the Impedance of Amorphous Ferromagnetic Wire
    Autorzy:
    Ziman, J.
    Šuhajová, V.
    Kladivová, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/1200635.pdf
    Data publikacji:
    2014-07
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.30.Gw
    75.47.-m
    75.50.Kj
    75.60.-d
    84.37.+q
    Opis:
    An experiment, measuring the changes of impedance in a magnetic wire, caused by the presence of a single domain wall was proposed. The results obtained from a magnetic wire with small helical anisotropy show that for lower frequencies (up to about 1 MHz), the presence of wall causes an increase in impedance, very probably due to the wall displacement. As frequency increases, the influence of the wall presence on the magnetic state causes the impedance to decrease in adjacent domains. For frequencies close to 10 MHz this effect overcomes the effect of wall displacement.
    Źródło:
    Acta Physica Polonica A; 2014, 126, 1; 82-83
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Magnetoelastic Villari Effect in Structural Steel Magnetized in the Rayleigh Region
    Autorzy:
    Kachniarz, M.
    Kołakowska, K.
    Salach, J.
    Szewczyk, R.
    Nowak, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/1030824.pdf
    Data publikacji:
    2018-03
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.30.-m
    75.60.-d
    75.50.Cc
    75.80.+q
    07.10.Lw
    Opis:
    The following paper presents the results of investigation on the magnetoelastic Villari effect in structural steel magnetized in the so-called Rayleigh region, which corresponds to relatively low magnetizing fields, much lower than coercive field. Two grades of structural steel were investigated during the performed measurements. Obtained results indicate significant correlation between applied mechanical stress and magnetic properties of the investigated materials.
    Źródło:
    Acta Physica Polonica A; 2018, 133, 3; 660-662
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Magnetoelastic Villari Effect in Ferrite Materials for Force and Stress Sensors Working in Low Magnetizing Field Region
    Autorzy:
    Kachniarz, M.
    Bieńkowski, A.
    Salach, J.
    Szewczyk, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/1030958.pdf
    Data publikacji:
    2018-04
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.30.-m
    75.60.-d
    75.50.Gg
    75.80.+q
    07.10.Lw
    Opis:
    The following paper presents the original results of investigation on the magnetoelastic properties of ferrite materials magnetized in low field region, which could be utilized in development of force and stress sensors. The objects of investigation were two ferrite materials (manganese-zinc Mn-Zn and nickel-zinc Ni-Zn). The magnetoelastic characteristics of the materials were investigated with the special measurement system, allowing measurement of magnetic parameters of the ferrite materials magnetized with low fields under the influence of the compressive stress. The obtained results indicate that there is a strong correlation between the magnetic properties of the material in low magnetizing field region, and applied mechanical stress, which allows development of the magnetoelastic stress or force sensor with ferrite core working in low magnetizing field region.
    Źródło:
    Acta Physica Polonica A; 2018, 133, 4; 1056-1059
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Effects of Gd/Ba Nonstoichiometry in $Gd_{1+x}Ba_{2-x}Cu_{3}O_{7-δ}$ on Superconducting and Magnetic Properties
    Autorzy:
    Majerová, M.
    Cigáň, A.
    Bystrický, R.
    Maňka, J.
    Dvurečenskij, A.
    Škrátek, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/1371559.pdf
    Data publikacji:
    2014-07
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    74.72.-h
    74.25.Ha
    75.30.Cr
    75.30.Et
    75.60.-d
    75.60.Ch
    75.60.Nt
    Opis:
    Effects of slight nonstoichiometry in $Gd_{1+x}Ba_{2-x}Cu_{3}O_{7-δ}$ compounds on superconducting and magnetic properties were studied. The series of single-phase samples of $Gd_{1+x}Ba_{2-x}Cu_{3}O_{7-δ}$ with composition deviation x from the stoichiometric value of 0 to 0.1 and to -0.1 were synthesized by the solid-state reaction method from $Gd_{2}O_{3}$, $BaCO_{3}$ and CuO precursors, sintered at the temperature of ~ 1000°C in flowing oxygen and annealed at 450°C for 24 h.
    Źródło:
    Acta Physica Polonica A; 2014, 126, 1; 354-355
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    AC Magnetic Properties of Vitroperm Based Composite Materials
    Autorzy:
    Kollár, P.
    Hegedüs, L.
    Füzer, J.
    Bureš, R.
    Fáberová, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/1533956.pdf
    Data publikacji:
    2010-11
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.50.Tt
    81.05.Ni
    85.70.-w
    75.60.-d
    75.50.Bb
    Opis:
    The aim of this work was to investigate the influence of resin content on AC magnetic properties of Vitroperm 800-based composite material to extend possibilities for application of this kind of material at higher frequency (up to 100 kHz). The samples of composite material were prepared in the form of the ring with outer diameter of 25 mm, inner diameter of 18 mm and height approximately 3 mm. Powder mixtures were prepared from Vitroperm 800 in partial nanocrystalline state and commercial termoset resins by mechanical mixing. The AC magnetic properties (losses) at maximum induction up to 0.5 T were measured by MATS-2010SA loop tracer in frequency range 1-100 kHz. The specific resistivity of the material was measured by the van der Pauw method. The magnetic properties of the composite rings were compared with the properties of the material prepared from Fe based powder supported by Höganäs. It was found out that the total losses of the Vitroperm-based soft magnetic composite are more than 10 times lower (at 10 kHz) than that for Fe-based one.
    Źródło:
    Acta Physica Polonica A; 2010, 118, 5; 787-789
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The Surface and Bulk Magnetic Properties of Fe-Al Alloys
    Autorzy:
    Hendrych, A.
    Životský, O.
    Jirásková, Y.
    Maťko, I.
    Powiązania:
    https://bibliotekanauki.pl/articles/1366608.pdf
    Data publikacji:
    2014-07
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.50.Bb
    75.70.Rf
    68.37.Rt
    78.20.Ls
    75.60.-d
    Opis:
    The present paper is devoted to Fe-Al alloys with aluminium content of 28, 33 and 35 at.%, prepared by standard technological procedure. The attention is focused on the comparison of the surface and bulk magnetic properties, which were obtained by magneto-optical Kerr effect (MOKE) and atomic and magnetic force microscopy (AFM/MFM) as the surface-sensitive methods combined with the vibration sample magnetometer (VSM) yielding the bulk magnetic properties. As was expected, the $Fe_{72}Al_{28}$ sample shows an overall ferromagnetic behavior at room temperature. Nevertheless, the bulk hysteresis loop shows single-phase behavior, while the surface MOKE hysteresis loop consists of two overlapped curves characterized by different coercivity values. The other two samples are paramagnetic from the viewpoint of the bulk, but reveal ferromagnetic behavior of their surfaces, represented by hysteresis loops, corresponding to rather harder magnetic phase. These results are well supported by MFM.
    Źródło:
    Acta Physica Polonica A; 2014, 126, 1; 58-59
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Mössbauer and Magnetic Study of Fe+Vitroperm+Plastic System
    Autorzy:
    Brzózka, K.
    Kollár, P.
    Szumiata, T.
    Sovak, P.
    Füzer, J.
    Fáberová, M.
    Bureš, R.
    Górka, B.
    Gawroński, M.
    Gzik-Szumiata, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/1201075.pdf
    Data publikacji:
    2014-07
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.50.Bb
    68.35.bd
    76.80.+y
    75.60.-d
    72.80.Tm
    Opis:
    Phase composition and magnetization curves of the soft magnetic composites, fabricated by compaction of several kinds of powders mixed in various proportions, have been investigated by means of conversion electron Mössbauer spectroscopy and an alternating gradient force magnetometry. The results point to significant quantity of iron oxides - hematite and magnetite - at the surface of the samples. After the rubbing of thin surface layer, the relative content of oxides was distinctly reduced. Magnetic measurements revealed very similar characteristics of hysteresis curves for all the investigated materials.
    Źródło:
    Acta Physica Polonica A; 2014, 126, 1; 148-149
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Magnetic Properties of Mechanochemically Synthesized Mixed Oxides
    Autorzy:
    Kostova, N.
    Zorkovská, A.
    Kováč, J.
    Velinov, N.
    Baláž, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/1372521.pdf
    Data publikacji:
    2014-07
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    77.84.Bw
    75.60.-d
    76.80.+y
    61.05.cp
    81.07.Wx
    Opis:
    The mixed oxides $Fe_{2}O_{3}-ZnO$ have been obtained in nanocrystalline state by reactive milling in a high-energy planetary mill, from a stoichiometric mixture of hematite and ZnO. The magnetic properties of samples were evaluated by magnetization measurements and Mössbauer spectrometry. A post milling annealing promotes the solid state reaction and improves the zinc ferrite formation, paramagnetic $ZnFe_{2}O_{4}$ phase is formed. Further mechanical activation leads to structural transformation into Wüstite-type (FeZn)O mixed oxide, with ferromagnetic hysteresis and increased magnetization.
    Źródło:
    Acta Physica Polonica A; 2014, 126, 1; 411-412
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Imaging of Magnetic Domain Structure in $FeSi/Mn_{0.8}Zn_{0.2}Fe_2O_4$ Composite using Magnetic Force Microscopy
    Autorzy:
    Streckova, M.
    Batko, I.
    Batkova, M.
    Bures, R.
    Faberova, M.
    Dzunda, R.
    Hadraba, H.
    Kubena, I.
    Powiązania:
    https://bibliotekanauki.pl/articles/1398262.pdf
    Data publikacji:
    2017-04
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    72.80.Tm
    75.50.Bb
    75.60.-d
    81.20.-n
    81.20.Ev
    81.20.Fw
    Opis:
    Soft magnetic composite was prepared by coating the commercial FeSi powder by $Mn_{0.8}Zn_{0.2}Fe_2O_4$ (MnZn) ferrite, which serves as a potential dielectric phase. MnZn ferrite was prepared by the sol-gel method followed by the auto-self combustion process. The spinel structure of MnZn ferrite was analyzed by X-ray diffraction technique. The composite material was prepared by uniaxial compaction technique and sintered either by conventional or unconventional microwave method. The microwave sintering was applied in order to reduce a grain growth and decrease the overall sintering time. The microstructure of FeSi powder is formed by grains of different diameter. Magnetic force microscopy and scanning electron microscopy were used for an investigation of the correlation between the grain size, grain boundaries and magnetic domains. Magnetic force microscopy visualization of magnetic domains in the prepared soft magnetic composite brings insight into how the magnetically active coating (MnZn ferrite) influences the soft magnetic (FeSi) powder under the influence of the external magnetic field.
    Źródło:
    Acta Physica Polonica A; 2017, 131, 4; 714-716
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Structural Mechanism of the High-Damping State Formation in the Fe-Mn-Si Shape Memory Alloys
    Autorzy:
    Udovenko, V. A.
    Polyakova, N. A.
    Turmambekov, T. A.
    Powiązania:
    https://bibliotekanauki.pl/articles/2011038.pdf
    Data publikacji:
    1999-08
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    61.16.-d
    75.50.Bb
    75.60.Ej
    75.80.+q
    Opis:
    The structural mechanism of the high-damping state formation in the Fe-Mn-Si alloys has been investigated using transition electron microscopy and logarithmic decrement measurements. The high level of the elastic energy dissipation was found to be connected with a reversible movement of the Shockley dislocations under the sign changing stress action. The Shockley dislocations density and mobility are controlled by the alloys compositions and prior deformation value. The increase in the dislocations density with the help of the special cycling treatments can improve the alloys damping capacity.
    Źródło:
    Acta Physica Polonica A; 1999, 96, 2; 307-310
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Bistability of (Ga,Mn)As Ferromagnetic Nanostructures Due to the Domain Walls Switching
    Autorzy:
    Andrearczyk, T.
    Wosiński, T.
    Mąkosa, A.
    Figielski, T.
    Wróbel, J.
    Sadowski, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/1791342.pdf
    Data publikacji:
    2009-11
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    73.50.Jt
    75.50.Pp
    75.30.Gw
    75.60.Ch
    85.75.-d
    Opis:
    We designed and investigated four-arm nanostructures, composed of two perpendicularly crossed stripes, fabricated from ferromagnetic (Ga,Mn)As layer by means of electron-beam lithography patterning and chemical etching. The nanostructures exhibit a bistable resistance behavior resulting from two configurations of magnetic domain walls in the central part of the structures. We demonstrate a possibility of switching between two stable resistance states in zero magnetic field by applying a pulse of either weak magnetic field or electric current through the structure.
    Źródło:
    Acta Physica Polonica A; 2009, 116, 5; 901-903
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Stress Monitoring in Steel Elements via Detection of AC Magnetic Permeability Changes
    Autorzy:
    Szumiata, T.
    Hibner, K.
    Dziewiecki, K.
    Mazur, Z.
    Gockiewicz, A.
    Gzik-Szumiata, M.
    Górka, B.
    Witoś, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/1030407.pdf
    Data publikacji:
    2018-03
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.80.+q
    75.60.Ej
    75.50.Bb
    75.30.Gw
    62.20.D-
    Opis:
    The influence of mechanical stress on low frequency AC magnetic permeability was studied. The cold-drawn bars with C45 steel were subjected to investigation. The tensile stress (within elastic regime) was applied by means of material testing machine. Simple measuring system was assembled, which consisted of: function generator with magnetizing coil, detection coil and precise AC voltmeter. The registered changes of induced voltage were proportional to the change of magnetic permeability of the stretched rods. The obtained results were almost frequency-independent due to low frequency limit (250-500 Hz, weak eddy currents, no spin-origin energy dissipation). A significant magneto-mechanical hysteresis was observed slightly evolving from cycle to cycle with tendency of stabilization. The extension of basic Stoner-Wohlfarth model of magnetic permeability allowed to fit the data reproducing hysteretic behavior and considering the relaxation of the internal stress. The proposed, low-cost method is suitable in the industrial applications for stress control in large-sized steel elements.
    Źródło:
    Acta Physica Polonica A; 2018, 133, 3; 719-721
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Perceptual Evaluation of the Effect of Threshold in Selective Mixing of Sounds
    Autorzy:
    Kleczkowski, P.
    Pluta, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/1196825.pdf
    Data publikacji:
    2014-04
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    43.60.Hj
    43.60.+d
    43.75.Zz
    43.66.Lj
    Opis:
    Signal processing methods make possible such a mixing of signals that their overlapping in the time-frequency plane is reduced. This can be achieved by reducing the number of overlapping signals by discarding contributions from weaker signals and leaving only contributions from stronger ones. When applied to acoustic signals, this is referred to by the authors as selective mixing of sounds. Previous research has shown, that this rule, when applied to signals of musical instruments can provide some perceptual advantages over simple adding up the sound sources. In this paper, an experiment was carried out to determine the threshold of the value of relative energy of sound sources to control the decision about discarding a contribution from a particular sound source.
    Źródło:
    Acta Physica Polonica A; 2014, 125, 4A; A-117-A-121
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Relaxation dynamics in the spin-1 Heisenberg antiferromagnetic chain after a quantum quench of the uniaxial anisotropy
    Autorzy:
    Woźniak, D.
    Drzewiński, A.
    Kamieniarz, G.
    Powiązania:
    https://bibliotekanauki.pl/articles/1058535.pdf
    Data publikacji:
    2016-12
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.10.Jm
    76.60.Es
    05.30.-d
    75.30.Gw
    Opis:
    In the framework of the matrix product state representation the effect of a sudden turning on of the uniaxial anisotropy on the time evolution of the Haldane state has been investigated. Depending on the value of the uniaxial anisotropy parameter, the calculations were derived within (or outside) the region where the Haldane gap survives. An exact expression for the time evolution of the Loschmidt echo has been derived and, moreover, its collapse and revival behaviour was captured. In addition, the non-local order parameter of a time evolving state was tracked, revealing two types of relaxations.
    Źródło:
    Acta Physica Polonica A; 2016, 130, 6; 1395-1400
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Influence of Yttrium Substitution οn the Electronic Structure and Magnetic Moment οf $Gd_{7-x}Y_{x}Pd_{3}$ (x = 0, 1, 2, 3, 4)
    Autorzy:
    Klimczak, M.
    Talik, E.
    Tran, V.
    Powiązania:
    https://bibliotekanauki.pl/articles/1810460.pdf
    Data publikacji:
    2009-01
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    71.20.Lp
    71.28.+d
    75.40.Cx
    75.60.Ej
    Opis:
    The electronic structure and magnetic properties of $Gd_{7-x}Y_{x}Pd_{3}$ (x = 0, 1, 2, 4) single crystals were examined. These compounds crystallized in the same crystal structure type $(Th_{7}Fe_{3})$ with the same c/a ratio of 0.63. A strongly anisotropic behavior of the magnetic and transport properties was found. Magnetic frustration and spin fluctuations on the palladium atoms are responsible for the complex magnetic properties of this ternary compound. As a part of current research we presented further characteristic of the $Gd_{7-x}Y_{x}Pd_{3}$ (x = 0, 1, 2, 4) single crystal.
    Źródło:
    Acta Physica Polonica A; 2009, 115, 1; 200-202
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Time Evolution of the Magnetic Chains with Uniaxial Anisotropy
    Autorzy:
    Woźniak, D.
    Drzewiński, A.
    Kamieniarz, G.
    Powiązania:
    https://bibliotekanauki.pl/articles/1385537.pdf
    Data publikacji:
    2015-02
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.10.Jm
    76.60.Es
    05.30.-d
    Opis:
    In the framework of the matrix product states representation the effect of the single-ion anisotropy on the time evolution of the initial state after a sudden quench of the local magnetic field has been investigated. The overlap of the initial and time-evolved states, so called the Loschmidt echo, magnetization profiles and correlation functions are presented.
    Źródło:
    Acta Physica Polonica A; 2015, 127, 2; 333-335
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Equivalence of Mechanical and Magnetic Force in Magnetic Shape Memory Effect
    Autorzy:
    Kopecký, V.
    Perevertov, O.
    Straka, L.
    Ševčík, M.
    Heczko, O.
    Powiązania:
    https://bibliotekanauki.pl/articles/1402147.pdf
    Data publikacji:
    2015-10
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    61.72.Mm
    75.78.Fg
    75.50.Cc
    75.70.Cn
    75.60.Ej
    62.20.D-
    Opis:
    High mobility of twin boundary is crucial for magnetic shape memory effect. The twin boundary can be moved by applied magnetic field or mechanical stress. In Ni-Mn-Ga 10M martensite there are two different, field movable, a-c twin boundaries type I and II due to monoclinic lattice. For single twin boundary of both types we experimentally evaluated the equivalence of magnetic and mechanical force and the validity of generally used energy model using direct stress-strain and magnetization measurements. For type II, highly mobile twin boundary, the equivalence seems to be valid and model broadly agrees with measurement. However, for type I the calculated magnetic stress is much larger than mechanical stress needed for twin boundary motion.
    Źródło:
    Acta Physica Polonica A; 2015, 128, 4; 754-757
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Lysozyme Amyloid Fibrils Doped by Carbon Nanotubes
    Autorzy:
    Majorošová, J.
    Tomašovičová, N.
    Mitróová, Z.
    Rajňák, M.
    Girman, V.
    Kopčanský, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/1030498.pdf
    Data publikacji:
    2018-03
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    61.48.De
    68.37.Lp
    68.37.-d
    75.60.Ej
    87.14.Ee
    Opis:
    Production of new composites for the creation of modern materials with desired properties is the key feature of nanotechnology. Despite the well known advantages of magnetic nanoparticles, the aim of the present study was to synthesize lysozyme amyloid fibrils from hen egg white and subsequently doped this solution with single walled carbon nanotubes and with the magnetite Fe₃O₄ labelled single walled carbon nanotubes. Transmission electron microscopy and polarization optical microscopy were used to obtain the structural and dimensional information about samples. Measurements of magnetic properties indicate the considerable increase of the saturation magnetization for solutions included the magnetite nanoparticles.
    Źródło:
    Acta Physica Polonica A; 2018, 133, 3; 588-590
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The influence of selected organic compounds on the corrosion of historical glass based on their state of preservation
    Autorzy:
    Greiner-Wronowa, E.
    Świt, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/1058515.pdf
    Data publikacji:
    2016-12
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    89.90.+n
    61.43.Fs
    07.60.Pb
    68.37.-d
    68.37.Hk
    81.70.-q
    07.07.Df
    07.75.+h
    81.40.Np
    Opis:
    The aim of this study was to investigate the influence of selected organic compounds such as acetic acid and formaldehyde on the historical glass objects of corrosion processes. This is a very important problem for the field of conservation and restoration of glass of art. Glass objects exhibited in museum display cases can be suffered by evaporating organic compounds which undergo to reaction with leached glass elements to create corrosion deposit on their surface. The proposed method called glass sensors has been used to identify results of impact of various external factors on the tested glass. Due to aggressive environment for the objects there created corrosion phenomena. Glass sensor were prepared as reproduced XVIII-cent. materials. The current studies were carried out by modern physico-chemical methods such as optical, metallography, scanning electron microscopy, inductively coupled plasma mass spectrometry and the Fourier transform infrared spectrometry. These techniques allow to determine the composition of the corrosion layers as well as their structure. The issues raised in this work have been studied following an interdisciplinary approach. The information obtained by using different techniques provides a valuable source of knowledge about the chemical reactions taking place on the surface of the glass. The results derived from this work are useful for the design and implementation of exhibition recommendations and better planning of conservation tasks.
    Źródło:
    Acta Physica Polonica A; 2016, 130, 6; 1406-1414
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-90 z 90

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