Magnetic Properties of RPd3S4 (R=Ce, Gd)

Magnetic properties of palladium sulfide bronzes RPd3S4 (R=Ce, Gd) are reported. They crystallize in a cubic platinum bronze type structure. Their magnetic susceptibilities were measured from 2 to 350 K. The initial magnetization and magnetic hysteresis loop were measured at 2 K by changing the applied magnetic field between -5 and 5 T. The electron paramagnetic resonance (EPR) spectrum of Gd3+ was also measured at room temperature. GdPd3S4 shows an antiferromagnetic behavior below 5.8 K. Above 10 K the magnetic susceptibility follows the Curie law, and the effective magnetic moment is determined to be 7.36 mu B. The magnetic moment is not saturated up to 5 T and no magnetic hysteresis has been found. From the EPR measurement the g value of Gd3+ in GdPd3S4 is determined to be 2.00. CePd3S4 shows ferromagnetism below 5.8 K. The residual magnetization is only 0.39 mu B and the magnetic moment at 5 T is 0.83 mu B at 2 K. This result shows that the ground state gamma 8 of Ce3+ is split into two Kramerʹs doublets by the crystal field. From the magnetic transition temperature of both GdPd3S4 and CePd3S4, the superexchange interaction is considered to be dominant in the magnetic interaction of these compounds.