ENHANCED INTERGRAIN TUNNELING MAGNETORESISTANCE IN HALF-METALLIC CRO2FILMS

Low-field tunneling magnetoresistance was observed in films of half-me tallic CrO2 that were grown by high-pressure thermal decomposition of CrO3. High-temperature annealing treatments modified the intergrain ba rriers of the as-grown films through surface decomposition of CrO2 int o insulating Cr2O3, which led to a threefold enhancement of the low-fi eld magnetoresistance. This enhancement indicates the potential of thi s simple method to directly control the interface barrier characterist ics that determine the magnetotransport properties.