Thermal exchange bias field drifts after 10 keV He ion bombardment: Storage temperature dependence and initial number of coupling sites

Sputter deposited Mn(83)Ir(17)(30 nm)/Co(70)Fe(30)(10 nm)/Ta thin films have been investigated for their thermal exchange bias field drift at different storage temperatures after 10 keV He(+) ion bombardment in an externally applied in-plane magnetic field. It is experimentally shown that the drift coefficient in an intermediate time interval, as given in a recently developed model, is proportional to T and proportional to the initial number of coupling sites in the polycrystalline exchange bias layer system used. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3665198]