Magnetic properties of R2Co17−xGax compounds (RSm and Gd)

Abstract

The magnetic properties of R2Co17−xGax compounds with 0≤x≤5 for RGd and 0≤x≤7 for RSm were studied by means of magnetic measurements and X-ray diffraction on magnetically aligned powders. The measurements have shown that increasing Ga concentration leads to a sign reversal of the magnetocrystalline Co-sublattice anisotropy from easy-plane anisotropy for low Ga concentration to easy-axis anisotropy for higher Ga concentration. In the Sm2Co17−xGax compounds, the Sm-sublattice anisotropy and the Co-sublattice anisotropy add constructively. This leads to materials of considerable magnetic hardness and the occurrence of narrow domain walls, in particular at relatively high Ga concentrations. There is a strong decrease of the Curie temperature with Ga concentration in both series.