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Sputter deposited Mn83Ir17(30 nm)/Co70Fe30(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. [ABSTRACT FROM AUTHOR]

The thermal exchange bias field drift of sputter deposited Mn83Ir17(15 nm)/Co70Fe30(10 nm)/Ta thin films at room temperature after 10 keV He+ ion bombardment in an externally applied in-plane magnetic field for different ion fluences was studied. Although field cooling of the layer system resulted in a temporally stable exchange bias field at room temperature the exchange bias field starts to drift after ion bombardment like in non-annealed samples. Between 1 and 648 h after ion bombardment a logarithmic increase in the absolute magnitude of the exchange bias field is observed. A tentative model is presented for its description based on noninteracting domains in the antiferromagnet. A comparison between experimental data and the model reveals the delicate interplay between the ion bombardment modified average antiferromagnetic anisotropy constants, exchange coupling constants, and relaxation time distributions in the polycrystalline layer system influencing the thermal drift velocities. [ABSTRACT FROM AUTHOR]

A new plasma ion source for in situ keV He ion bombardment of solid state samples or thin films was designed and built for ion fluences between 1 × 1012 and 1 × 1017 ions/cm2. The system was designed to be mounted to different diffraction chambers for soft x-ray resonant magnetic scattering. Without breaking the vacuum due to He-ion bombardment, structural and magnetic modifications of the samples can be studied in situ and element specifically. [ABSTRACT FROM AUTHOR]