We report on the observation of a field-induced magnetic bias effect in a Ga0.94Mn0.06As1-yPy thin film with digitally graded phosphorus content. Although phosphorus concentration in the sample is changed in steps from y≈0.03 to y≈0.28, the magnetometry and magnetotransport data display a coherent magnetic response typical for single-layer in-plane magnetized films with cubic and weak  uniaxial anisotropy. Unexpectedly, low-temperature planar Hall resistance loops exhibit remarkable asymmetry tunable by application of strong in-plane initial magnetic field HIni. We discuss this unusual memory effect, resembling the magnetization asymmetry in the exchange biased magnetic bilayers, in terms of a unidirectional bias field Hb induced by HIni. We show that such bias field defines the delayed or accelerated nucleation of domains with chiral domain walls performing the magnetization reversal.
ASJC Scopus subject areas
- Materials Science(all)
- Physics and Astronomy (miscellaneous)