Spin Reorientations in RTiFe11 Systems (R = Tb, Dy and Ho).

摘要

The compound SmTiFe11 has been reported to possess high uniaxial magnetocrystalline anisotropy. This high anisotropy is a result of the fact that both the rare earth and transition metal sublattices favor an axial orientation. Since, in this structure, Sm prefers the magnetization to lie long the c-axis those rare earths with negative second order Stevens' factors, such as Tb, Dy and Ho, are likely candidates to exhibit Type 2 spin reorientations, due to competing anisotropies of the rare earth and transitions and show that the nature of the spin reorientation (axis-to-plane in the case of Tb, and axis-to-cone in the case of Dy and Ho) correlates with the sign of the fourth order Stevens factor. It is further shown that, with the exception of the cone-to-plane transition of the Dy system, these spin reorientations can be explained in terms of the thermal evolution of the first and second anisotropy constants, K1 and K2. Reprints. (js)