Abstract
Temperature dependences of the magnetocrystalline anisotropy constant, K1, and the magnetostriction constants, λ100 and λ111 were determined for alloy single crystals with concentrations of 4.8 wt% Si, 5.0 wt% AI, bal Fe and 4.7 wt% Si, 3.8 wt% Al, bal Fe, respectively. The temperature dependence and the magnitude of K1 for each alloy were found to be completely different : K1=9.1 × 103 erg/cm3 for the former and 1.1 × 105 erg/cm3 for the latter alloys at room temperature, respectively. The values of λ100 and λ111 (× 10-6) at room temperature were found to be 4.8, 9.8 for the former and 7.8, 5.7 for the latter alloys. A unique diffraction line due to the existence of the D03 type of ordered structure was clearly observed for both alloys. From the results obtained, it may be concluded:
1) The discrete change of the values of K1 exists at the phase boundary between α and α + D03 phases,
ii) The magnitude of K1 for the alloys consisting of the D03 ordered phase is smaller than that of α + D03 phase.
