Enhancement of Room Temperature Magnetoresistance in La_0.7Sr_0.3Mn_1-xCu_xO₃

抄録

A series of perovskite-type compounds La_0.7Sr_0.3Mn_1−xCu_xO₃ have been synthesized by solid state reaction with x=0,0.03,0.05,0.08,0.10,0.15,0.20,0.25,0.30. The Curie temperature and transition temperature of metal-insulator decreases when x value increases from 0 to 0.20. There is an enhancement of magnetoresistance ΔR⁄R₀ of compounds La_0.7Sr_0.3Mn_1−xCu_xO₃ at room temperature which may be connected with the shift of Curie temperature and transition temperature of metal-insulator through Cu atom substitution. On the contrary, the increase of resistivity is due to the reduction of the double-exchange interaction.