Controlled rotation of the exchange-bias direction in IrMn/Cu/Co via ion irradiation

Abstract

Co/Cu/IrMn films were irradiated with 40 keV He+ ions varying the fluence and the current, with magnetic field applied at 120° with respect to the original exchange-bias direction. The angular variations of the exchange-bias field of the irradiated samples were compared with those of the as-made and the thermally annealed films. Gradual deviation of the exchange-bias direction with the fluence increase was observed. Complete reorientation of the easy axes of both ferromagnet and antiferromagnet toward that of the field applied during irradiation was achieved for fluences higher than 1 1015 ions/cm2, accompanied with a significant enhancement of the exchange-bias field.