Transport, thermal and magnetic properties of RuSr_2(Gd_{1.5}Ce_{0.5})Cu_2O_{10-\delta}, a magnetic superconductor

摘要

Resistivity, thermoelectric power, heat capacity and magnetization forsamples of RuSr_2(Gd_{1.5}Ce_{0.5})Cu_{2}O_{10-\delta} were investigated in thetemperature range 1.8-300 K with a magnetic field up to 8 T. The resistivetransitions to the superconducting state are found to be determined by theinhomogeneous (granular) structure, characterized by the intragranular, T_{c0},and intergranular, T_{cg}, transition temperatures. Heat capacity, C(T), showsa jump at the superconducting transition temperature T_{c0}\approx 37.5 K. ASchottky-like anomaly is found in C(T) below 20 K. This low temperature anomalycan be attributed to splitting of the ground term $^{8}S_{7/2}$ of paramagneticGd^{3+} ions by internal and external magnetic fields.