Crystal field analysis of the magnetic properties of RFe₁₁Ti and RFe₁₁TiH (R=Sm, Tb, Ho)

The crystalline-electric-field parameters A_nm for RFe₁₁Ti and RFe₁₁TiH (R=Sm,Tb,Ho) are evaluated by fitting calculations to the magnetization curves measured on the single crystals or on magnetically aligned powder samples at 4.2K and higher temperatures. Interstitial hydrogen atom in RFe_11Ti has been found to have a significant effect on crystalline-electric-field parameters A_nm. By using the parameters of exchange field 2\mu_BH_ex estimated from inelastic neutron scattering experiments and the fitted A_nm, the calculations can reproduce the experimental curves well.