Magnetic properties of RPd3S4 (R = Ce, Gd)

Magnetic properties of palladium sulfide bronzes RPd3S4 (R = Ce, Gd) are re ported. They crystallize in a cubic platinum bronze type structure. Their m agnetic susceptibilities were measured from 2 to 350 K. The initial magneti zation and magnetic hysteresis loop were measured at 2 K by changing the ap plied magnetic field between -5 and 5 T. The electron paramagnetic resonanc e (EPR) spectrum of Gd3+ was also measured at room temperature. GdPd3S4 sho ws an antiferromagnetic behavior below 5.8 K. Above 10 It the magnetic susc eptibility follows the Curie law, and the effective magnetic moment is dete rmined 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 valu e 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 magnet ic moment at 5 T is 0.83 mu(B) at 2 K. This result shows that the ground st ate Gamma(8) of Ce3+ is split into two Kramer's doublets by the crystal fie ld. From the magnetic transition temperature of both GdPd3S4 and CePd3S4, t he superexchange interaction is considered to be dominant in the magnetic i nteraction of these compounds. (C) 1999 Academic Press.