Electrical Properties of ZnCr2Se4

The experiments of the electrical resistivity and magnetoresistance effect were performed on undoped p-type ZnCr2Se4 single crystals and Cu-substituted ZnCr2Se4 single crystals between room temperature and below T N. Hall effect was also measured with Cu-substituted ZnCr2Se4 between 300 K and 4K. Remarkable variations were observed at ∼114 K and ∼22 K in the temperature dependence of electrical resistivity of any undoped samples. Negative magnetoresistance was also observed below ∼110 K and it increases with a peak in the vicinity of T N. Anisotropy of the resistivity with respect to the crystallographic axes was recognized though it was small. High sensitive measurement of differential thermal analysis was carried out and anomalies of its signal were observed at ∼110 K, ∼64 K, ∼36 K and ∼22 K. These results seem to indicate the interdependence between magnetic and electrical properties which is the characteristic of ZnCr2Se4.