ORIENTATIONAL DEPENDENCE OF THE EXCHANGE BIASING IN MOLECULAR-BEAM-EPITAXY-GROWN NI80FE20/FE50MN50 BILAYERS

The exchange biasing field (Hb) and coercive field (H(c)) of molecular-beam-epitaxy-grown Cu/Ni80Fe20/Fe50Mn50 Samples in [111], [001], and [110] orientations have been investigated by longitudinal Kerr effect measurements. Ni80Fe20 and Fe50Mn50 were deposited as orthogonal wedge-shaped layers on single-crystal Cu substrates in a magnetic field, enabling the study of the thickness dependence of H(eb) and H(c) on a single sample for each orientation. A strong dependence of H(eb) and H(c) on the growth orientation is observed. The results are interpreted in terms of the observed noncollinear spin structure of the antiferromagnet and a comparison is given with the predictions from recent theoretical models.