MAGNETIC-PROPERTIES OF RTICO11 COMPOUNDS WITH THE THMN12 STRUCTURE

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-mu-B, 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 x 10(6) 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 x 10(6) 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.