Study of spin-reorientation in Tm2Fe17-xGax and Sm2Fe17-xGax

In order to compare their anisotropy behavior, Tm2Fe17-xGax and Sm2Fe17-xGa x (0 less than or equal to x less than or equal to 8) powders were magnetic ally aligned using either static-field or dynamic-field methods. Magnetizat ion measurements were carried out along both the easy and hard magnetic dir ections for temperatures 10 less than or equal to T less than or equal to 3 50 K and fields up to 50 kOe. Spin-reorientation behavior was observed in a ll of the Tm2Fe17-xGax samples studied; the nature of the anisotropy depend s on both the Ga content and temperature. In Tm2Fe17-xGax for x = 0, 1, 3, and 5, the anisotropy changes from uniaxial to easy-plane with increasing t emperature; while for x = 7 and 8, the anisotropy changes from easy-plane t o uniaxial. In contrast, none of the Sm2Fe17-xGax samples studied show spin -reorientation behavior. For Sm2Fe17-xGax with x = 0, 6, 7, and 8, the anis otropy is easy-plane, while with x = 1, 2, 3, 4, and 5, the anisotropy is u niaxial; the nature of the anisotropy does not change with temperature over the range of measurement. The results are discussed in terms of the effect of Ga substitution on the Tin-sublattice and Sm-sublattice anisotropies.