Transport, Heat Capacity and Magnetization of the Magnetic Superconductor RuSr_(2)(Gd_(1.5)Ce_(0.5))Cu_(2)O_(10-delta)

摘要

Samples of RuSr_(2)(Gd_(1.5)Ce_(0.5))Cu_(2)O_(10-delta) have been studied. Resistivity, thermopower, heat capacity and magnetization were investigated in the temperature range 1.8-300 K under a magnetic field up to 8 T. The resistive transitions to the superconducting state are found to be determined by a granular structure, so that the intragranular, T_(c0), and intergranular, T_(cg), transition temperatures were found. Heat capacity, C(T), shows a jump at the superconducting transition, corresponding to intragranular superconductivity (with T_(c0) approx= 37.5 K). A Schottky-like anomaly is found in C(T) below 20 K. The possible reasons for this anomaly (associated with rare-earth Gd ions) are considered.