Magnetic and electrical properties of Gd5M3 (M=Sn and Sb) single crystals

Magnetic and electrical properties of Gd5Sn3 and Gd5Sb3 single crystals have been studied. Gd5Sn3 possesses an antiferromagnetic state below T N=60 K and another antiferromagnetic phase transition has been found at T t=35 K. On the other hand, Gd5Sb3 shows ferromagnetic state below T C=187 K and a canted or ferrimagnetic state could exist below T t=50 K. Both compounds have no magnetic anisotropy in the paramagnetic susceptibility indicating Curie-Weiss law. Though the effective magnetic moment μ eff is in reasonable agreement with the theoretical value of Gd3+ in Gd5Sn3, a large μ eff value was obtained in Gd5Sb3. Electrical resistivity shows anomalies at the transition temperatures. In the c-plane of Gd5Sn3, electrical resistivity increases slightly with decrease in temperature below about 200 K