Spin valve effect across the metal-insulator transition in V2O3

The magnetoresistance of Ni/V2O3/Py devices shows interesting behavior in the temperature dependence across the V2O3 metal-insulator transition. A spin-valve effect (∼0.1%) is found below the transition temperature when V2O3 is in the insulating phase. Contrary to expectation, the spin-valve effect disappears when device is heated above 150 K and V2O3 is in the metallic state. At these temperatures, the behavior of the device is governed by anisotropic magnetoresistance of Ni. Using finite method analysis of our device we show that disappearance of the spin-valve effect cannot be explained by changes in the current distribution with temperature.