Nonmonotonic behavior of magnetoresistance, R(H) hysteresis, and low-temperature heat capacity of the BaPb{sub 0.75}Bi{sub 0.25}O{sub 3} superconductor in a magnetic field: Possible manifestations of phase separation

Journal Article · Thu Apr 15 04:00:00 EDT 2010 · Journal of Experimental and Theoretical Physics

DOI:https://doi.org/10.1134/S1063776110040059· OSTI ID:21443561

Dubrovskiy, A A; Popkov, S I; Shaikhutdinov, K A ^[1]; Mart'yanov, O N ^[2]; Petrov, M I ^[1]

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1. Russian Academy of Sciences, Kirenskii Institute of Physics, Siberian Branch (Russian Federation)
2. Russian Academy of Sciences, Boreskov Institute of Catalysis, Siberian Branch (Russian Federation)

The transport properties (R(T) and R(H) dependences at various values of the transport current in magnetic fields up to 65 kOe) and low-temperature heat capacity in magnetic fields up to 90 kOe of the BaPb{sub 0.75}Bi{sub 0.25}O{sub 3} superconductor (T{sub C} {approx} 11.3 K) are investigated with the goal of clarifying the mechanisms determining the nonmonotonic behavior and hysteresis of its magnetoresistance R(H). The type of R(H) hysteretic dependences for BaPb{sub 0.75}Bi{sub 0.25}O{sub 3} is analogous to that observed in granular high-T{sub c} superconductors (HTSCs); however, unlike classical HTSC systems, the field width of the magnetoresistance hysteresis loop for polycrystalline BaPb{sub 0.75}Bi{sub 0.25}O{sub 3} depends on the transport current. This means that although the mechanisms responsible for the magnetoresistance hysteresis (the influence of the magnetic flux trapped in superconducting regions on the effective field in Josephson interlayers) are identical in these objects, the transport current in BaPb{sub 0.75}Bi{sub 0.25}O{sub 3} may considerably affect the diamagnetic response of the superconductor. A considerable effect of transport current on the field in which the R(H) dependences have a peak and exhibit hysterestic properties is observed. Such a behavior can be adequately interpreted using the model of the spatially inhomogeneous superconductor-insulator state proposed by Gorbatsevich et al. [JETP Lett. 52, 95 (1990)]. The nonmonotonic dependence of quantity C/T (C is the heat capacity) on the magnetic field discovered in the present study also agrees with the conclusions based on this model.

• OSTI ID: 21443561
• Journal Information: Journal of Experimental and Theoretical Physics, Journal Name: Journal of Experimental and Theoretical Physics Journal Issue: 4 Vol. 110; ISSN 1063-7761
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BISMUTH COMPOUNDS
BISMUTH OXIDES
CHALCOGENIDES
CRYSTALS
CURRENTS
ELECTRIC CONDUCTIVITY
ELECTRIC CURRENTS
ELECTRICAL PROPERTIES
HIGH-TC SUPERCONDUCTORS
HYSTERESIS
JOSEPHSON JUNCTIONS
LEAD COMPOUNDS
MAGNETIC FIELDS
MAGNETIC FLUX
MAGNETORESISTANCE
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
POLYCRYSTALS
SPECIFIC HEAT
SUPERCONDUCTING JUNCTIONS
SUPERCONDUCTORS
TEMPERATURE DEPENDENCE
THERMODYNAMIC PROPERTIES
TRAPPING
TYPE-II SUPERCONDUCTORS