We have studied exchange bias and coercivity in ferromagnetic (FM) Ni81 Fe19 layers coupled with antiferromagnetic (AF) (0001), (11 2- 0), and (1 1- 02) α- Fe2 O3 layers. We show that the exchange interaction between FM and AF layers is controllable by a magnetic-field annealing (MFA) through a spin reorientation temperature of an AF material, similar to a MFA through a Ǹel temperature in normal exchange-biased systems. For (11 2- 0) and (1 1- 02) α- Fe2 O3, the temperature-dependent exchange bias displayed a sudden increase below a spin-flip temperature of α- Fe2 O3 (Tm) and the coercivity showed a clear variation near Tm.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)
- Physics and Astronomy(all)