Structure and temperature dependence of the magnetization of the DyFe11Ti nanocrystalline compound

Abstract

The coercive force, the temperature dependence of the magnetization, and the structure of a DyFeTi alloy based on the DyFe11Ti compound with an excess content of α-Fe in the initial coarse-grained, nanocrystalline, and submicrocrystalline states are investigated experimentally. It is found that, in the submicrocrystalline sample, the coercive force is three times stronger and the temperature of the first spin-reorientation transition is 20 K higher than those in the coarse-grained sample. In the nanocrystalline sample, the coercive force is five times stronger than that in the coarse-grained sample, the first spin-reorientation transition is not revealed, and the transition at the Curie temperature is smeared. It is demonstrated that the changes observed in the magnetic properties are unrelated to the phase transformations but stem from the small size of crystal grains and high imperfection of the structure. The thermal instability of the DyFe11Ti compound is observed in submicrocrystalline and nanocrystalline states.