High thermal stability of exchange-biased bilayers and bottom giant magnetoresistive spin valves using an α-Fe2O3 antiferromagnetic layer

The thermal stability of antiferromagnetic α-Fe2O3 exchange-biased bilayers and bottom giant magnetoresistive (GMR) spin valves has been investigated experimentally at various ambient temperatures. An α-Fe2O3 exchange-biased bilayer exhibited a high blocking temperature, Tb, of 390 °C, and a bottom spin valve showed stable GMR performance above 350 °C. The Tb of α-Fe2O3 exchange-biased bilayers depended strongly on the adjacent ferromagnetic material and the number of measurements. In addition, the increasing mean grain size and enhanced (104) and (110) crystalline texture of α-Fe2O3 increased Tb by up to 23%.