Tuning exchange-bias properties by thermal effects in a hard/soft bilayer

Abstract

The effect of temperature on exchange-bias properties of an antiferromagnetically coupled hard/soft bilayer (Tb12 Fe88 Gd40 Fe60) is studied. In a similar manner to its cooling field dependence, a continuous transition from a negative to a positive exchange-bias field is observed with increasing temperature. The changes of magnetic configuration responsible for this effect are studied, combining both magnetization and polarized neutron reflectivity measurements. The temperature is found to enhance the exchange-bias training effect as a result of the relaxation of an interface domain wall. The present study demonstrates that both temperature and cooling field may be used to tune the exchange field. © 2007 American Institute of Physics.