Enhanced Intergrain Tunneling Magnetoresistance in Half-Metallic CrO 2 Films

Abstract

Low-field tunneling magnetoresistance was observed in films of half-metallic CrO 2 that were grown by high-pressure thermal decomposition of CrO 3 . High-temperature annealing treatments modified the intergrain barriers of the as-grown films through surface decomposition of CrO 2 into insulating Cr 2 O 3 , which led to a threefold enhancement of the low-field magnetoresistance. This enhancement indicates the potential of this simple method to directly control the interface barrier characteristics that determine the magnetotransport properties.