Transport, Heat Capacity and Magnetization of the Magnetic Superconductor RuSr2(Gd1.5Ce0.5) Cu2O10-δ.

Samples of RuSr2(Gd1.5Ce0.5)Cu2O10-δ 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, Tc0, and intergranular, Tcg, transition temperatures were found. Heat capacity, C(T), shows a jump at the superconducting transition, corresponding to intragranular superconductivity (with Tc0 ≈ 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. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]