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Pis'ma v Zhurnal Èksperimental'noi i Teoreticheskoi Fiziki, 2002, Volume 75, Issue 3, Pages 166–174
(Mi jetpl3154)
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CONDENSED MATTER
Anomalous transport properties of a paramagnetic NiTiO$_3$ + HTSC two-phase system representing a random Josephson junction network
M. I. Petrov, D. A. Balaev, K. A. Shaykhutdinov, S. I. Popkov L. V. Kirensky Institute of Physics, Siberian Branch of the Russian Academy of Sciences, Krasnoyarsk
Abstract:
Composites representing a network of random Josephson junctions and characterized by the compositions 92.5 at.% ${\rm Y_{3/4}Lu_{1/4}Ba_2Cu_3O_7+7.5}$ at.% NiTiO$_3$ and 92.5 at.% ${\rm Y_{3/4}Lu_{1/4}Ba_2Cu_3O_7+7.5}$ at.% MgTiO$_3$ are synthesized, and their magnetoresistance properties are studied. The temperature dependence of the resistance $R(T)$ measured for the composite that contains the paramagnetic NiTiO$_3$ compound exhibits a characteristic feature below the superconducting transition temperature $T_c$ of the high-$T_c$ superconductor, namely, a region where $R$ is independent of the current $j$ and weakly depends on the magnetic field $H$. Below a certain temperature $T_m$, a strong dependence of $R$ on $j$ and $H$ is observed, which is peculiar to a network of Josephson junctions. The dependences $R(T, j, H)$ obtained for the «reference» samples with the nonmagnetic MgTiO$_3$ compound exhibit no such features. The anomalous behavior of the HTSC + NiTiO$_3$ composite is explained by the effect produced by the magnetic moments of Ni atoms in the insulating barriers on the transport current.
Received: 12.10.2001 Revised: 26.12.2001
Citation:
M. I. Petrov, D. A. Balaev, K. A. Shaykhutdinov, S. I. Popkov, “Anomalous transport properties of a paramagnetic NiTiO$_3$ + HTSC two-phase system representing a random Josephson junction network”, Pis'ma v Zh. Èksper. Teoret. Fiz., 75:3 (2002), 166–174; JETP Letters, 75:3 (2002), 138–141
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https://www.mathnet.ru/eng/jetpl3154 https://www.mathnet.ru/eng/jetpl/v75/i3/p166
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Abstract page: | 146 | Full-text PDF : | 53 | References: | 36 |
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