Low-temperature behavior of specific heat curves in ruthenocuprate RuSr2Gd1.5Ge0.5Cu2O10 − δ: Superconducting, magnetic and crossing-point effects

Autor: Donald G. Naugle, K. D. D. Rathnayaka, Glenn Agnolet, B. I. Belevtsev, V. B. Krasovitsky, Israel Felner
Rok vydání: 2010
Předmět:
Zdroj: Bulletin of the Russian Academy of Sciences: Physics. 74:1049-1052
ISSN: 1934-9432
1062-8738
Popis: Magnetic and superconducting properties of polycrystalline samples of RuSr2Gd1.5Ce0.5Cu2O(10 − δ), asprepared (by solid-state reaction) and annealed in pure oxygen at different pressure are presented. Specific heat and magnetization were investigated in the temperature range 1.8–300 K with a magnetic field up to 8 T. Specific heat, C (T), shows a jump at the superconducting transition (with onset at T ≈ 37.5 K) and a Schottky-type anomaly below 20 K. It is found that curves C(T) taken for different values of magnetic field have the same crossing point (at T* ≈ 2.7 K) for all samples studied. At the same time, C(H) curves taken for different temperatures have a crossing point at a characteristic field H* ≈ 3.7 T. These effects are manifestations of the crossing-point phenomenon, which is supposed to be inherent for strongly correlated electron systems.
Databáze: OpenAIRE
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