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

Abstract: The magnetic and electrical transport behaviors of Cr3(Se1−x Te x )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 (ρ min) is observed in the temperature dependence of resistivity. The temperature T min, where the minimum ρ min is, increases with Te concentration. The minimum in resistivity at T min 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 T min is described by hopping conductivity in terms of variable range—hopping. An external magnetic field affects strongly the resistivity of the Cr3(Se1−x Te x )4 compounds, which shifts the magnetic ordering temperature T MO to higher temperature and T min to lower temperature. Subsequently, a negative magnetoresistance is found in this system. [Copyright &y& Elsevier]