Magnetic and electrical transport properties of Cr3(Se1−xTex)4 compounds

The magnetic and electrical transport behaviors of Cr3(Se1−xTex)4 compounds are investigated. A transition from antiferromagnetism to ferromagnetism occurs at x = 0.2 in this system and abnormal changes of the lattice parameter a and angle β take place around the magnetic transition point. When Se is partially substituted by Te, a minimum of resistivity (ρmin) is observed in the temperature dependence of resistivity. The temperature Tmin, where the minimum ρmin is, increases with Te concentration. The minimum in resistivity at Tmin is ascribed to the competition between a diminishing resistivity due to domain ordering and a rising resistivity due to disordered frozen spins in each domain. The electrical transport behavior below Tmin is described by hopping conductivity in terms of variable range—hopping. An external magnetic field affects strongly the resistivity of the Cr3(Se1−xTex)4 compounds, which shifts the magnetic ordering temperature TMO to higher temperature and Tmin to lower temperature. Subsequently, a negative magnetoresistance is found in this system.