Determination of Structural Anisotropy of Stress-Annealed Fe $_{80.5}$ Ga $_{19.5}$

The origin of the induced magnetic anisotropy in stress-annealed single crystalline Fe_80.5Ga_19.5 was investigated by high energy X-ray diffuse scattering. A compressive stress was applied along [010] during annealing. Superlattice reflections associated with D0₃ chemical order were analyzed to clarify the origin of the stress-annealing-induced magnetic anisotropy. Results showed that the D0₃ precipitates in the microstructure exhibited long range ordering of Ga. These clusters were found not to have a crystallographic preference relative to the applied stress axis and no structural anisotropy could be detected. The results indicate that the induced anisotropy following stress annealing likely comes from the anisotropy of the magnetic domain alignment and is not related to the underlying microstructural features of the alloy.