Microstructural Dependence of Magnetization and Magnetostriction in Fe-20at.%Ga
A combination study of magnetic and magnetostrictive properties in directionally cast and differently heat-treated Fe-20Ga(at.%) samples has been carried out at room temperature. Slow cooling leads to an increase in the occupation of [200] easy magnetic axes; however, a structural ordering of Ga atoms into a metastable D03 phase decreasesthe saturation magnetostriction (λs) and the saturation magnetization (Ms), and increases coercivity (Hc).Our results confirm the contribution of D03 ordering to magnetic and magnetostrictive properties due to their pinning effects against magnetic domain wall motions. As compared to slow cooling, water quenching suppresses the formation of metastable (D03) or stable (L12) ordered phases and preserves the A2 single phase structure down to room temperature, leading to enhanced magnetostriction and magnetization.