Magnetocrystalline Anisotropy and Magnetostriction for Fe-(4 to 6 wt%) Si-(2 to 5 wt%) Al Alloy Single Crystals

The temperature dependences of the magnetocrystalline anisotropy constant K1 and the magnetostriction constants ¿100 and ¿111 were measured for Fe-Si-Al alloy single crystals in the composition range 4 to 6 wt% Si, 2 to 5 wt% Al, balance Fe, after being slowly cooled from 1200°C or quenching from 1200°C. The crystal structure of these single crystal samples was determined by electron diffraction. The large difference in the magnitudes of K1=9.1×10³ erg/cm³ for 4.8 wt% Si, 5.0 wt% Al, bal. Fe alloy, and K1=9.1×10⁵ erg/cm³ for 4.7 wt% Si, 3.8 wt% Al, bal. Fe alloy was found to be connected with the difference in their crystal structures. The ¿100=0 and ¿111=0 equal-value line were identified on a composition diagram. The concentration of the alloy at which the second peak in ¿m occurs is located along the ¿100 = 0 line Moreover, this second peak alloy may have the Do3 structure.