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 λgammaof 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,-3.2×10⁷,-0.9×10⁷and0.41×10⁷ergs/cm3, respectively. The magnetostriction coefficient λγwas determined by the strain gage technique. The contribution of the Tb ion to the magnetostriction constant λγof 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.