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

The thermal stability of antiferromagnetic alpha -Fe2O3 exchange-biased bil ayers and bottom giant magnetoresistive (GMR) spin valves has been investig ated experimentally at various ambient temperatures. An alpha -Fe2O3 exchan ge-biased bilayer exhibited a high blocking temperature, T-b, of 390 degree sC, and a bottom spin valve showed stable GMR performance above 350 degrees C. The T-b of alpha -Fe2O3 exchange-biased bilayers depended strongly on th e adjacent ferromagnetic material and the number of measurements. In additi on, the increasing mean grain size and enhanced (104) and (110) crystalline texture of alpha -Fe2O3 increased T-b by up to 23%. (C) 2001 American Inst itute of Physics.