Magnetic anisotropy of YFe11Ti and its hydride

A study of the magnetic anisotropy of single-crystal YFe11Ti and of its hydride is reported. The measurements were performed on a vibrating-sample and a torsion magnetometer on field-oriented single-crystal and powder samples. The temperature dependence of the magnetic anisotropy constants K-1 and K-2 was determined by a mathematical treatment of experimental torque curves and by applying the Sucksmith-Thompson technique to magnetization data. It is shown that the temperature dependence of the magnetic anisotropy constants of YFe11Ti and of its hydride does not follow the prediction of the single-ion exchange model. It is found that hydrogenenation results in a growth of the magnetic anisotropy constant, which can be explained by an electron-density redistribution near the lattice positions occupied by iron atoms. (C) 1998 American Institute of Physics.