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Tytuł:
Magnetoresistance and Intrinsic Pinning of Vortices in the Untwinned $YBa_2Cu_3O_{7 - δ}$ Single Crystals with Optimal Oxygen Content and a Small Deviation from the Oxygen Stoichiometry
Autorzy:
Vovk, R.
Gvozdikov, V.
Obolenskii, M.
Nazyrov, Z.
Kruglyak, V.
Powiązania:
https://bibliotekanauki.pl/articles/1427580.pdf
Data publikacji:
2012-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.25.Fy
74.25.Qt
Opis:
We study the temperature dependence of the in-plane magnetoresistance $ρ_{ab}(T)$ in untwinned $YBa_2Cu_3O_{7 - δ}$ single crystals with the optimal oxygen content and with a small deficit of oxygen atoms at different angles between the external magnetic field 15 kOe and the ab-planes α. We found that at high temperatures in the pseudogap region external magnetic field does not affect the $ρ_{ab}(T)$ but it broadens transitional region $T_{c} - T_{c0}$ from 0.3 K at zero field and α = 0 to approximately 6 K at α = 60° in the field. In case of optimal doping the function $ρ_{ab}(T)$ display a 3D to 2D dimensional crossover when temperature decreases from $T_{c}$ to $T_{c0}$ and scaling near the $T_{c0}$ which we relate to the flux-flow and vortex-lattice melting. In the underdoped sample the vortices are effectively pinned by the random oxygen vacancies and the function $ρ_{ab}(T)$ in transitional region has smooth tails without any traces of crossover and scaling.
Źródło:
Acta Physica Polonica A; 2012, 121, 5-6; 1191-1194
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of Electromagnetic Phenomena in HTc Superconductors
Autorzy:
Sosnowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/1812341.pdf
Data publikacji:
2008-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.25.Qt
74.25.Sv
Opis:
Unique electromagnetic properties, especially concerning recent observations of the giant remanent magnetic moment in HTc superconductors, require new approach to modeling these phenomena in the oxide ceramics. The present paper is devoted to the analysis of the influence of flux pinning on critical current and flux trapping in HTc superconductors. Modeling of the interaction between nanosized pinning centers and pancake vortices is presented, allowing to determine critical current density, taking into account elasticity forces of the vortices lattice. Ceramic structure of oxide superconductors was considered in trapped flux analysis. The mechanism of trapped flux generation was regarded as strongly related to vortex pinning and critical current phenomena.
Źródło:
Acta Physica Polonica A; 2008, 114, 1; 269-274
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Size Effect in Impedance of Nb$\text{}_{3}$Al Superconductor
Autorzy:
Aleksyeyev, P.
Nabiałek, A.
Vasiliev, S.
Rusakov, V.
Chabanenko, V.
Zalutskii, M.
Piechota, S.
Szymczak, H.
Kodess, B. N.
Powiązania:
https://bibliotekanauki.pl/articles/2046746.pdf
Data publikacji:
2006-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.25.Qt
74.70.Ad
Opis:
We present the results of the impedance measurements in Nb$\text{}_{3}$Al superconducting polycrystalline alloy vs. temperature and magnetic field. Using these results and applying the size effect model we calculate the flux-flow conductivity of the Nb$\text{}_{3}$Al superconducting alloy near its critical temperature.
Źródło:
Acta Physica Polonica A; 2006, 109, 4-5; 555-559
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Oscillating Dynamics and Trajectory of the Single Vortex Line
Autorzy:
Rusakov, V.
Vasiliev, S.
Chabanenko, V. V.
Yurov, A.
Nabiałek, A.
Piechota, S.
Szymczak, H.
Powiązania:
https://bibliotekanauki.pl/articles/2046795.pdf
Data publikacji:
2006-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.25.Qt
74.70.Ad
Opis:
The De Gennes and Matricon problem of finding the spectrum of oscillations of massive vortex line under the action of pinning and viscosity forces is solved. The obtained vibration spectrum of the vortex is discussed and the role of each contributing force is elucidated. The trajectory of the vortex motion is calculated and illustrated.
Źródło:
Acta Physica Polonica A; 2006, 109, 4-5; 641-646
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Low-Field Ac Impedance of YBa$\text{}_{2}$Cu$\text{}_{3}$O$\text{}_{7-δ}$ Superconducting Slab
Autorzy:
Aleksyeyev, P. O.
Reusenblatt, E. M.
Powiązania:
https://bibliotekanauki.pl/articles/2047229.pdf
Data publikacji:
2007-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.25.Qt
74.70.Ad
Opis:
Using results of surface impedance measurements, the penetration of ac field into a melt-textured YBa$\text{}_{2}$Cu$\text{}_{3}$ O$\text{}_{7-δ}$ slab was investigated. We obtained a linear correlation between the surface impedance and ac frequency. The impedance curve shifts towards higher temperatures - 0.9 K per decade of the frequency increase, for dc magnetic fieldμ$\text{}_{0}$H$\text{}_{dc}$≤8×10$\text{}^{-3}$ T. This is an evidence of thermally activated flux creep. A plateau in the temperature dependence of the real impedance part was observed at approximately 88 K.
Źródło:
Acta Physica Polonica A; 2007, 111, 1; 99-104
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Macroscopic Quantum Tunnelling of Josephson Vortex in Antiferromagnetic Superconductor
Autorzy:
Krzysztoń, T.
Powiązania:
https://bibliotekanauki.pl/articles/1812296.pdf
Data publikacji:
2008-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.20.De
74.25.Qt
Opis:
The influence of antiferromagnetic order on high temperature superconductor could possibly result in creation of spin-flop domain along the phase core of the Josephson vortex. In this paper we discuss how this feature affects the activation energy of the macroscopic quantum tunnelling of the Josephson vortex.
Źródło:
Acta Physica Polonica A; 2008, 114, 1; 171-174
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Influence of the Pinning Centres Dimensions on the Critical Current in High-T$\text{}_{c}$ Superconductors
Autorzy:
Sosnowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/2041525.pdf
Data publikacji:
2004-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.25.Qt
74.72.-h
Opis:
An analysis of the influence of the pinning centres dimensions on the critical current and pinning forces of the high temperature oxide superconductors is presented. Individual interaction of the pinning centres with pancake type vortices is considered for the layered structure of the copper-oxide superconductors. The phenomenological model was elaborated in which the change of the system energy has been constructed taking into account the pinning interaction, Lorentz forces, and elastic energy of the vortex lattice. The resistivity criterion has been used for detection of the critical current. Especially important results have been obtained for the range of the pinning centres dimensions smaller than twice the value of the coherence length.
Źródło:
Acta Physica Polonica A; 2004, 106, 5; 767-770
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dynamics of Thermomagnetic Avalanches in Melt-Textured YBaCuO Superconductors
Autorzy:
Nabiałek, A.
Vasiliev, S.
Aleksyeyev, P.
Chabanenko, V.
Powiązania:
https://bibliotekanauki.pl/articles/2047241.pdf
Data publikacji:
2007-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.72.Bk
74.25.Qt
Opis:
We investigated dynamics of the thermomagnetic avalanche development in melt-textured samples of the oxide YBaCuO high temperature superconductor. We found that the flux jumps, caused by the thermomagnetic instabilities, are accompanied by giant convergent oscillations of the surface induction. These results are compared with the dynamics of the flux jumps in other type-II superconductors, including conventional NbTi and oxide high temperature Bi $\text{}_{2}$Sr$\text{}_{2}$CaCu$\text{}_{2}$O$\text{}_{8+δ}$ superconductor, and discussed in the framework of the available model of the thermomagnetic avalanche development.
Źródło:
Acta Physica Polonica A; 2007, 111, 1; 153-158
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optical Properties of a Semimagnetic Quantum Well in a Proximity of a Superconducting Film
Autorzy:
Lebecki, K. M.
Kłopotowski, Ł.
Kossut, J.
Powiązania:
https://bibliotekanauki.pl/articles/2044492.pdf
Data publikacji:
2005-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.67.De
74.25.Qt
Opis:
We consider, via numerical calculations, a hybrid structure made of a semimagnetic Cd$\text{}_{1-x}$Mn$\text{}_{x}$Te quantum well deposited in a close proximity to superconducting niobium film. We simulate photoluminescence and the Faraday rotation spectra, modified by the presence of vortices in this type II superconductor. The magnitude of the evaluated effects is small - the vortex induced spectral line shape variation is of the order of 1% at 1 K and 0.1% at 3 K and is expected to occur mainly in the field range between 0.03 T and 0.05 T.
Źródło:
Acta Physica Polonica A; 2005, 108, 5; 741-748
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Easy Vortex Motion in an Artificial Channel of $YBa_2Cu_3O_{7-δ}$ Superconducting Films
Autorzy:
Jukna, A.
Barboy, I.
Jung, G.
Abrutis, A.
Li, X.
Wang, D.
Sobolewski, R.
Powiązania:
https://bibliotekanauki.pl/articles/1813381.pdf
Data publikacji:
2008-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.25.Sv
74.25.Qt
74.78.Bz
Opis:
Quasi-Josephson effect produced by a coherent vortex motion in the horizontal part of the laser-performedΠ-shaped channel of a $YBa_2Cu_3O_{7-δ}$ superconducting bridge was investigated by means of electric transport measurements. We observed that in our structures, in a limited range of temperatures and bias currents, the vortices were confined in the channel only and moved coherently with the velocity of $3×10^4$ m/s. The corresponding current-voltage characteristics of the bridge exhibited Josephson-like voltage steps with the amplitude dependent on temperature, but independent of the bias current.
Źródło:
Acta Physica Polonica A; 2008, 113, 3; 959-962
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Influence of Fast Neutron Irradiation on the Magnetostriction of Ceramic YBa$\text{}_{2}$Cu$\text{}_{3}$O$\text{}_{7-δ}$ Sample
Autorzy:
Nabiałek, A.
Vasiliev, S.
Pytel, B.
Chabanenko, V. V.
Piechota, S.
Powiązania:
https://bibliotekanauki.pl/articles/2041474.pdf
Data publikacji:
2004-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.25.Qt
74.72.Bk
75.80.+q
Opis:
We investigated the magnetostriction of ceramic YBa$\text{}_{2}$Cu$\text{}_{3}$O$\text{}_{7-δ}$ sample both before and after fast neutron irradiation with the fluency of 7.55×10$\text{}^{17}$ n/cm$\text{}^{2}$ and energy of above 0.5 MeV. We have found that after irradiation the widths of both transverse and longitudinal magnetostriction hysteresis loops at a given temperature and at a given external magnetic field increased several times. At 4.2 K and in 10 tesla the widths of the magnetostriction hysteresis loop of the irradiated sample are of an order of 10$\text{}^{-5}$. The results can be understood in the framework of the model of the magnetostriction induced by the pinning forces, assuming the stress in the sample to be induced mainly by the intragrain screening currents.
Źródło:
Acta Physica Polonica A; 2004, 106, 5; 739-744
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Magnetic Field on Resistive Transition of Thin Film Thallium Based Superconductors
Autorzy:
Woch, W. M.
Zalecki, R.
Kołodziejczyk, A.
Chmist, J.
Heiml, O.
Gritzner, G.
Powiązania:
https://bibliotekanauki.pl/articles/2041534.pdf
Data publikacji:
2004-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.78.Bz
74.25.Qt
74.62.Yb
Opis:
The temperature and magnetic field dependences of a.c. resistance of c-axis oriented (Tl$\text{}_{0.5}$Pb$\text{}_{0.5}$)(Sr$\text{}_{0.8}$Ba$\text{}_{0.2}$)$\text{}_{2}$Ca $\text{}_{2}$Cu$\text{}_{3}$O$\text{}_{x}$ and (Tl$\text{}_{0.6}$Pb$\text{}_{0.24}$Bi$\text{}_{0.16}$)(Sr$\text{}_{0.9}$Ba$\text{}_{0.1}$)$\text{}_{2}$Ca$\text{}_{2}$Cu$\text{}_{3}$ O$\text{}_{x}$ thin films as well as of (Tl$\text{}_{0.5}$Pb$\text{}_{0.5}$)(Sr$\text{}_{0.8}$Ba$\text{}_{0.2}$)$\text{}_{2}$Ca$\text{}_{ }$2Cu$\text{}_{3}$O$\text{}_{x}$ bulk sample from 77 K to room temperature and in magnetic fields from zero to 3000 Oe were measured and analyzed. The magnetic field and temperature dependence of the resistive superconducting transition and irreversibility field were discussed both in the flux-creep model and in the superconducting liquid vortex state model. The temperature width of resistive transition was explained taking advantage of the Ambegaokar and Halperin model of the resistance of superconducting Josephson weak links and barrier of vortex motion presented by Tinkham. The irreversibility field was described by an exponential formula.
Źródło:
Acta Physica Polonica A; 2004, 106, 5; 785-791
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Vortex Pinning in Ferromagnet/Superconductor Bilayers - the Dependence on the Ferromagnetic Layer and Temperature
Autorzy:
Adamus, Z.
Cieplak, M. Z.
Abal'oshev, A.
Berkowski, M.
Kończykowski, M.
Cheng, X. M.
Shu, L. Y.
Chien, C. L.
Powiązania:
https://bibliotekanauki.pl/articles/2046703.pdf
Data publikacji:
2006-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.25.Ha
74.25.Qt
74.78.Db
74.78.Fk
Opis:
The behavior of vortex pinning induced by the magnetic domain reversal is studied in the ferromagnet/superconductor bilayers in which superconducting film is niobium and the ferromagnetic layers are the Co/Pt superlattices with perpendicular magnetic anisotropy. The local magnetic field across narrow ferromagnet/superconductor bilayer stripe is measured using a line of miniature Hall sensors. The pinning is studied for samples with different amount of repeats of Co/Pt superlattice, and as a function of temperature.
Źródło:
Acta Physica Polonica A; 2006, 109, 4-5; 451-456
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Giant Magnetostriction Jumps in Conventional NbTi Superconductor
Autorzy:
Nabiałek, A.
Vasiliev, S.
Chabanenko, V.
Aleksyeyev, P.
Rusakov, V.
Piechota, S.
Szymczak, H.
Powiązania:
https://bibliotekanauki.pl/articles/2046793.pdf
Data publikacji:
2006-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.25.Qt
74.70.Ad
75.80.+q
Opis:
Magnetostriction of a large slab of conventional NbTi superconductor, with a diameter of about 6 mm, was investigated by the strain gauge technique. At the temperature of 4.2 K and in the external magnetic field of several T we found irreversible magnetostriction of an order of 10$\text{}^{-5}$, where the number means the relative changes of the slab diameter. This large magnetostriction is accompanied by giant magnetostriction jumps, caused by thermomagnetic avalanches. These thermomagnetic avalanches also cause giant jumps of the surface magnetization, which can be observed by using the Hall probes. The results were analyzed in the framework of the pinning induced magnetostriction model.
Źródło:
Acta Physica Polonica A; 2006, 109, 4-5; 633-639
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Vortex Dynamics in Ferromagnetic/Superconducting Bilayers
Autorzy:
Cieplak, M.
Adamus, Z.
Kończykowski, M.
Zhu, L.
Chien, C.
Powiązania:
https://bibliotekanauki.pl/articles/1812264.pdf
Data publikacji:
2008-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.25.Ha
74.25.Qt
74.78.Db
74.78.Fk
Opis:
The dependence of vortex dynamics on the geometry of magnetic domain pattern is studied in the superconducting/ferromagnetic bilayers, in which niobium is a superconductor, and Co/Pt multilayer with perpendicular magnetic anisotropy serves as a ferrromagnetic layer. Magnetic domain patterns with different density of domains per surface area and different domain size, w, are obtained for Co/Pt with different thickness of Pt. The dense patterns of domains with the size comparable to the magnetic penetration depth (w≥λ) produce large vortex pinning and smooth vortex penetration, while less dense patterns with larger domains (w ≫ λ) enhance pinning less effectively and result in flux jumps during flux motion.
Źródło:
Acta Physica Polonica A; 2008, 114, 1; 23-28
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł

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