Crystal field analysis of the magnetization curves of R2Fe17 and R2Fe17H3 (R=Tb,Ho,Er)

In this paper the values of the crystalline-electric-fieldparameters A_nm for R₂Fe₁₇ andR₂Fe₁₇H₃ (R=Tb,Ho,Er) are evaluated by fittingcalculations to the magnetization curves measured on the singlecrystal at several temperatures. The fitted A_nm forR₂Fe₁₇ are strikingly different from those for thecorresponding R₂Fe₁₇H₃. The energy gaps between thelowest four energy levels for Ho ions in Ho₂Fe₁₇₂ can bereproduced by using the fitted A_nm and exchange field2μ_BH_ex, which estimated from the fit of thetemperature dependence of the spontaneous magnetization combinedwith inelastic neutron scattering experiment.