Magnetocrystalline anisotropy In Fe-Mn-Ga magnetic shape memory alloy

摘要

Magnetocrystalline anisotropy of the martensite phase was investigated in a single crystal of Fe_(44)Mn_(28)Ga_(28) shape memory alloy. It was found that the martensite phase of Fe_(44)Mn_(28)Ga_(28) alloy has a tetragonal distorted L2_1 structure, with a = 0.5368 nm and c = 0.7081 nm. An approximately single variant was obtained by thermomechanical treatment, and magnetization measurement revealed that the c-axis is the magnetic easy axis. The magnetocrystalline anisotropy constant K_u was determined to be 7.6 x 10~5 J m~(-3) at 300 K.