Magnetic anisotropy of LuFe sub 11 Ti compound and its hydride and nitride

Magnetic anisotropy of LuFe sub 11 TiH sub x (x = 0, 1) single crystals and magnetically oriented powder samples of LuFe sub 11 TiN sub x (x = 1) were investigated. The anisotropy study has been performed by means of torque and magnetization measurements. The temperature dependencies of the magnetocrystalline anisotropy constants were determined using both least-squared fitting for the corrected experimental torque curves and from the magnetization isotherms along the hard [100] direction using the Sucksmith-Thompson relation. The lattice parameters, Curie temperature and saturation magnetization are increased by both hydrogenation and nitrogenation. The easy c-axis anisotropy is enhanced in the hydrides but decreased in the nitrides. The volume expansion and change of local environment of Fe ions after hydrogenation and nitrogenation lead to the effects observed.