Magnetization and Magnetocrystalline Anisotropy of Y_1-<i>x</i>R_<i>x</i>Co₅(R=Pr and Sm) Compounds

Abstract

The magnetizations of pseudo-binary Y 1- x R x Co 5 (R=Pr, Sm) single crystal compounds were measured at 4.2 K along the principal crystallographic axes. The magnetic moment per formula unit increases linearly with increasing x . The estimated values of the magnetic moments of Co atom in the compounds are independent of x and R elements. The magnetocrystalline anisotropy constants K 0 2 and K 0 4 were determined from the analysis of the hard magnetization curve. The values of K 0 2 and K 0 4 for Pr compound system increase quadratically with increasing x , and those of Sm compound system increase almost linearly with increasing x . We estimated the contribution of the single ion anisotropy and the two ion anisotropy for PrCo 5 and SmCo 5 compounds. For PrCo 5 compound, the two ion anisotropy constant was the same order of magnitude as the single ion one and of opposite sign to it, and for SmCo 5 compound, the former is negligibly smaller than the latter. The calculated value of the single ion anisotropy constant using point charge model is compared with the experiments.