Thermal and magnetic properties of GaV₄S₈

A polycrystalline GaV₄S₈ was prepared by re-sintering the sintered compound at 500°C for 10days. In this compound, we have found three anomalies around 179K, 43K and 13K. The 179K anomaly on GaV₄S₈ is noticed for the first time in resistivity, Seebeck coefficient and magnetization. According to the resistivity analysis, this is expected to be associated with the crossover from nearest neighbour to variable range hopping conduction. In comparison to previous results, this compound has a significantly large Seebeck coefficient within our measurement range. In addition to this, we have also found three Weiss temperatures i.e. +14.3K, -10.2K, +2.7K instead of two with effective paramagnetic moments 1.44/μ_B, 1.35/μ_B, 1.35/μ_B in 16 - 30K, 43 - 179K, 187 - 300K regions respectively from inverse susceptibility due to the existence of 179K anomaly.