Influence of stress on the magnetic domain structure in Fe81Ga19 alloys

Grains, grain boundaries, magnetic domain distributions, and their correlations in Fe81Ga19 alloys as-cast, annealed, and under compressive and grinding stresses were investigated using scanning electron acoustic microscopy (SEAM) and magnetic force microscopy (MFM). For as-cast and annealed samples, the main domain structure obtained using SEAM is not clear. For samples under stresses, the main domains are obvious and regular. For the sample under compressive stress, its stripe domains array orderly and perpendicularly to the stress direction. The subdomains of as-cast sample observed using MFM show a clear dendritic structure. However, for the sample under compressive stress, the subdomains are irregular. These results may be helpful to understand the magnetostrictive behavior of Fe–Ga alloys under stress.