Magnetization, magnetocrystalline anisotropy and magnetostriction of Tb2Co17, Ho2Co17and Er2Co17single crystals

This paper describes the temperature dependence of magnetization, the anisotropy constant K1and the magnetostriction constant λ^gammaof single crystals of Tb2Co17, Ho2Co17and Er2Co17over the temperature range 77.4°K to 400°K. Tb2Co17and Ho2Co17have a uniformly easy magnetization in the basal plane while Er2Co17maintains an easy C axis over the entire temperature range. The anisotropy constant K1was determined by a least square fit of the theoretical equation of magnetization to the measured magnetization curve along the hard axis. The anisotropy constant K1at 297°K for Tb2Co17, Ho2Co17and Er2Co17is,-3.2\times10^{7},-0.9\times10^{7}and0.41\times10^{7}ergs/cm³, respectively. The magnetostriction coefficient λ^γwas determined by the strain gage technique. The contribution of the Tb ion to the magnetostriction constant λ^γof the R2Co17compound is positive whereas the contribution of the Ho ion is negative. The magnetostrictive behavior of the Tb ion is single ion in nature.