Tuning perpendicular magnetic anisotropy in (Ga,Mn)(As,P) by thermal annealing

We have investigated the effects of postgrowth low temperature annealing on the magnetic, electrical, and structural properties of (Ga0.94Mn0.06)(As0.9P0.1) layers grown by molecular beam epitaxy. By controlling the annealing time, we are able to tune the magnetic anisotropy between an easy axis in the plane for the as-grown samples, to an easy axis perpendicular to the plane for fully annealed samples. The increase in the carrier density, as a result of annealing, is found to be the primary reason for the sign reversal of the magnetic anisotropy, in qualitative agreement with theoretical predictions.