In-plane to perpendicular magnetic anisotropy switching in heavily-Fe-doped ferromagnetic semiconductor (Ga,Fe)Sb with high Curie temperature
We report switching of magnetic anisotropy (MA) from in-plane to perpendicular with increasing the thickness d of a (001)-oriented ferromagnetic-semiconductor (FMS) (G a0.7,F e0.3 )Sb layer with a high Curie temperature (TC>320 K), using ferromagnetic resonance at room temperature. We show that the total MA energy (E⊥) along the  direction changes its sign from positive (in-plane) to negative (perpendicular) with increasing d above an effective critical value dC*∼42 nm . We reveal that (Ga,Fe)Sb has twofold symmetry in the film plane. Meanwhile, in the plane perpendicular to the film including the in-plane  axis, the twofold symmetry with the easy magnetization axis along  changes to fourfold symmetry with the easy magnetization axis along <001 > with increasing d . This peculiar behavior is different from that of (Ga,Mn)As, in which only the in-plane MA depends on the film thickness and has fourfold symmetry due to its dominant cubic anisotropy along the <100 > axes. This work provides an important guide for controlling the easy magnetization axis of high-TC FMS (Ga,Fe)Sb for room-temperature device applications.
Physical Review Materials
- Pub Date:
- August 2019
- Condensed Matter - Materials Science
- Phys. Rev. Materials 3, 084417 (2019)