Magnetic properties of <i>R</i>TiCo11 compounds with the ThMn12 structure

Abstract

Magnetic properties of RTiCo11 (R=Y, La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, and Er) compounds with the ThMn12 structure were investigated in the temperature range from 4.2 to 1400 K. The Curie temperatures of this series exceed 1000 K and the Co atomic moments were found to take the values ranging from 0.99 to 1.80 μB, which depend on R. The easy magnetization direction of RTiCo11 was found to be axial(c∥) for R except being planar for R=Sm and Er. This result suggests that the R sublattice with a positive Stevens factor demonstrates planar anisotropy. The Co sublattice anisotropy constant was estimated to be K1 = 7.5 × 106 erg/cc at room temperature from measurements on YTiCo11. By subtracting K1 of YTiCo11 from K1 of DyTiCo11, the anisotropy constant of the Dy sublattice was obtained to be 5.7×106 erg/cc. Spin reorientation was also observed in RTiCo11 with R=Pr, Nd and Dy, which are considered to be an axial to planar one with increasing temperature.