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

TL;DR

This study investigates the electrical, thermal, and magnetic properties of a magnetic superconductor RuSr_2(Gd_{1.5}Ce_{0.5})Cu_2O_{10-eta} across a broad temperature range, revealing inhomogeneous superconducting transitions and magnetic anomalies.

Contribution

It provides new insights into the interplay of magnetic and superconducting properties in Ru-based cuprates, highlighting the inhomogeneous nature of the superconducting transition and magnetic effects on heat capacity.

Findings

Superconducting transition is inhomogeneous, with distinct intra- and intergranular T_c.

Heat capacity shows a jump at T_c ≈ 37.5 K, indicating bulk superconductivity.

A Schottky anomaly below 20 K suggests magnetic splitting of Gd^{3+} ions.

Abstract

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