Magnetic, structural, and thermal properties of CoV2O4

In this paper, we investigate the electric, magnetic, structural, and thermal properties of spinel CoV2O4. The temperature dependence of magnetization shows that, in addition to the paramagnetic-to-ferrimagnetic transition at T-C = 142 K, two magnetic anomalies exist at 100 K, T-1 = 59 K. Consistent with the anomalies, the thermal conductivity presents two valleys at 100 K and T-1. At the temperature T-1, the heat capacity shows one peak, which cannot be attributed to the structural transition as revealed by the x-ray diffraction patterns for CoV2O4. Below the transition temperature T-1, the ac susceptibility displays the characteristics of a glass. The series of phenomena at T-1 and the orbital state on V3+ sites are discussed.