Magnetic anisotropy of FeGa alloys

Cubic magnetocrystalline anisotropy constants, K-1 and K-2, for Fe1-xGax alloys were measured using magnetization curves with x=0.05, 0.125, 0.14, 0.18, and 0.20. Thin circular (110) disks all with <100>, <110>, and <111> in the plane of the disk were used to measure K-1 and K-2. K-1 was also measured with (100) circular disks. K-1 for 5 at. % Ga content was found to be larger than that of pure Fe. (All compositions mentioned hereafter are atomic percents.) K-1 and K-2 both drop gradually up to 18 at. % Ga substitution. Then there is a sharp drop in the magnitude of both constants. K-2 was found to be equal to -9K(1)/4 and the <110> and <111> directions were equally hard magnetically for all compositions considered in this study. Calculation of the anisotropy energy density verifies this result. K-1 measured from both (110) and (100) disks was reasonably consistent. (C) 2004 American Institute of Physics.