Temperature dependence of the magnetic anisotropy and magnetostriction of Fe100−xGax (x=8.6, 16.6, 28.5)

The temperature dependence of the lowest order magnetic anisotropy constant K1 and the lowest order saturation magnetostriction constant, (3∕2)λ100, were measured from 4 K to 300 K for Fe91.4Ga8.6,Fe83.4Ga16.6, and Fe71.5Ga28.5 and were compared to the normalized magnetization power law, ml(l+1)∕2. Fe91.4Ga8.6 maintains the magnetostriction anomaly of Fe (dλ100∕dT>0) and K1 is a reasonable fit to the ml(l+1)∕2 power law with K1(0K)≅90kJ∕m3. Fe83.4Ga16.6 does not show a magnetostriction anomaly, but fits the power law remarkably well. Fe71.5Ga28.5 possesses a small K1(∼1kJ∕m3) at all temperatures and a large temperature dependent magnetostriction, reaching ∼800ppm at low temperature.