Magnetic and structural transitions of GeV4S8

Successive phase transition of the cubic (F (4) over bar3) compound GeV4S8 has been studied by the magnetic susceptibility, the specific heat and the neutron diffraction experiments. In the temperature dependences of the susceptibility and the specific heat, two anomalies have been observed at T-S = 33 and T-N = 18 K. Sharp peaks in the specific heat at T-S and TN indicate that both transitions are of the first order. The neutron diffraction revealed that, GeV4S8 undergoes successive structural phase transitions from cubic to rhombohedral (R3m) at T-S, and to orthorhombic (Imm2) at T-N With the decrease of temperature. Consequently, the antiferromagnetic ordering at T-N is found to be accompanied with the structural transition. (c) 2006 Elsevier B.V. All rights reserved.