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Wyszukujesz frazę "Bureš, R." wg kryterium: Autor


Wyświetlanie 1-15 z 15
Tytuł:
Imaging of Magnetic Domains and Domain Walls in Spherical Fe-Si Powder Using Magnetic Force Microscopy
Autorzy:
Strečková, M.
Baťková, M.
Baťko, I.
Hadraba, H.
Bureš, R.
Powiązania:
https://bibliotekanauki.pl/articles/1367241.pdf
Data publikacji:
2014-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Bb
75.60.Ch
75.70.Kw
Opis:
The commercial Fe-Si powder, produced by Högänes Corporation, represents promising soft magnetic material for technological applications. The powder consists of spherical particles with diameter up to 150 μm. Internal microstructure of the powder is formed by grains of diameter of about 30 μm. Each separate grain has a random orientation of the easy magnetization axis and is sufficiently large to split into several magnetic domains. A comparative study of the atomic force microscopy (AFM) topography and the corresponding magnetic force microscopy (MFM) images was employed in order to examine the correlation between the grain size, boundaries of grains and characterization of the magnetic domains, which gives us an important knowledge about possible behavior of particles under the influence of the external magnetic field and further utilization of the spherical Fe-Si particles in electrotechnical industry. The grain size and the crystallographic orientation of grains were analyzed by the electron backscattering diffraction (EBSD) technique.
Źródło:
Acta Physica Polonica A; 2014, 126, 1; 92-93
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:
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:
Advances in Powder Metallurgy Soft Magnetic Composite Materials
Autorzy:
Bureš, R.
Strečková, M.
Fáberová, M.
Kollár, P.
Füzer, J.
Powiązania:
https://bibliotekanauki.pl/articles/353238.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
resin bonded SMC
soft magnetic ferrites
compaction
microwave sintering
magnetic and mechanical properties
Opis:
Powder metallurgy has grown with the expansion of various industry. Automotive industry had the most strong influence. Today, more than 90% of PM products are used in the transportation industry. Development of new materials such as magnetic materials is expected to meet the new trends of automotive industry, electric and hybrid vehicles. Soft magnetic composites (SMC) are PM materials based on ferromagnetic powder particles covered by electric insulation layer. Concept of SMC’s and PM technologies offer possibility to become faster, use higher frequencies, become smaller and denser, save more energy, achieving high permeability and lower core loss in high frequency region, which is required for soft magnetic materials. Investigation of correlations among compaction parameters, inner structure, magnetic and mechanical properties are presented.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 2B; 1149-1154
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
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:
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:
Structure and Properties of Composites Based on Mixed Morphology of Ferromagnetic Particles
Autorzy:
Bureš, R.
Fáberová, M.
Strečková, M.
Birčáková, Z.
Kollár, P.
Füzer, J.
Powiązania:
https://bibliotekanauki.pl/articles/1200815.pdf
Data publikacji:
2014-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.05.-t
75.50.Bb
Opis:
Application potential of the soft magnetic composites increases with improvement of their functional properties. In addition to the magnetic properties, the mechanical properties of these materials are essential. The aim of this work was to investigate mechanical properties and their dependence on morphology of the ferromagnetic particles. Model composite based on Somaloy® and Vitroperm® powder was prepared using conventional powder metallurgy. The DC magnetic properties of composites based on two types of ferromagnetic particles with different shapes and structures are discussed in the relation with mechanical properties.
Źródło:
Acta Physica Polonica A; 2014, 126, 1; 140-141
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:
Microwave Sintered Fe/MgO Soft Magnetic Composite
Autorzy:
Bureš, R.
Fáberová, M.
Kollár, P.
Füzer, J.
Dobák, S.
Onderko, F.
Kurek, P.
Powiązania:
https://bibliotekanauki.pl/articles/1032291.pdf
Data publikacji:
2017-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.05.-t
75.50.-y
62.20.-x
Opis:
Micro/nano soft magnetic composite based on the Fe microparticles and the MgO nanoparticles was prepared by cold pressing followed by microwave sintering. Magnetic and mechanical properties of the green compact as well as sintered samples were measured. Coercivity, permeability, resistivity, elastic modulus and transverse rupture strength values in dependence on MgO content were investigated. The influence of MgO content ratio on properties was different in the case of as pressed green samples in comparison to sintered bodies. Microstructure formation and its influence on mechanical and magnetic properties are discussed. The coercivity of the green compacts with 1-5 wt% of MgO exhibits approximately 460 A/m and after sintering decreases to approximately 290 A/m. The real part of complex permeability at the frequency of 100 kHz exhibits a maximum for 2 wt% of MgO in green compacts, while for 10 wt% in sintered samples. It was observed that increase of the content of MgO causes decrease of the permeability. Properties of the sintered composite are related to formation of magnesium ferrite as well as volume distribution of residual MgO in dependence on initial MgO ratio.
Źródło:
Acta Physica Polonica A; 2017, 131, 4; 780-782
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
FeSiBAlNiMo High Entropy Alloy Prepared by Mechanical Alloying
Autorzy:
Bureš, R.
Hadraba, H.
Fáberová, M.
Kollár, P.
Füzer, J.
Roupcová, P.
Strečková, M.
Powiązania:
https://bibliotekanauki.pl/articles/1032753.pdf
Data publikacji:
2017-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.05.-t
75.50.Tt
75.50.Kj
62.20.-x
Opis:
High-entropy alloys have attracted increasing attentions because of their unique compositions, microstructures, and adjustable mechanical and functional properties. In this work, mechanical and magnetic properties of the FeSiBAlNiMo high-entropy alloy were studied in heat-treated conditions. Influence of temperature and time of sintering was investigated. The lowest coercivity H_c=370 A/m was reached at sintering temperature 580°C, during 20 min in Ar/10H₂ atmosphere. Resistivity decreases from R=0.006 Ωcm at 580°C of sintering temperature to R=0.0004 Ωcm at temperature 1100°C. Transverse rupture strength TRS = 340 MPa as well as the Young modulus E=87 GPa were much higher in the case of sintering at 1100°C in comparison to TRS = 5 MPa and E=7.5 GPa at sintering temperature 580°C. Low temperature consolidation made possible to structure recovery and stress relief of amorphous-nanocrystalline structure. Higher temperature above 1100°C induced sintering processes and formation of complex borides.
Źródło:
Acta Physica Polonica A; 2017, 131, 4; 771-773
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:
Magnetic Properties of Sintered Fe₅₀Co₅₀ Powder Cores
Autorzy:
Olekšáková, D.
Kollár, P.
Füzer, J.
Onderko, F.
Dobák, S.
Viňáš, J.
Fáberová, M.
Bureš, R.
Powiązania:
https://bibliotekanauki.pl/articles/1032708.pdf
Data publikacji:
2017-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Vv
85.70.-w
75.50.Bb
Opis:
We investigated coercivity, total losses and complex permeability of sintered Fe-Co powder cores to detect magnetization processes performing in ac magnetic field. The Fe-Co solid solution alloy powders with 50:50 wt% ratio were prepared by 1, 15, and 20 h alloyed mixture of pure chemical elements in planetary ball mill. The resulting powder was subsequently sintered into a disk form. The compaction was performed at a pressure of 800 MPa for 5 min at temperatures of 400°C, 500°C and 600°C in vacuum oxidation protective atmosphere, with pressure of 5×10¯³ Pa. The best magnetic properties exhibit sample prepared from 1 h alloyed powder, compacted at 600°C.
Źródło:
Acta Physica Polonica A; 2017, 131, 4; 807-809
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:
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:
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
    Wyświetlanie 1-15 z 15

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