Crystal fields of dilute Tb, Dy, Ho, or Er in Lu obtained by magnetization measurements

Magnetization measurements are reported on single crystals of dilute Tb, Dy, Ho, or Er in Lu. These measurements were performed in the temperature range 1.5-100 K and field range 0-6 T and include measurements of initial susceptibility, isothermal and isofield magnetization, and basal-plane anisotropy. The results show features similar to the corresponding $\mathrm{Y}-R$ alloys, where $R$ is a rare earth. Crystal-field and molecular-field parameters could be unabiguously deduced from the experimental data. The effects of crystal-field level broadening were investigated and demonstrated for Ho. Comparison of the $\mathrm{Y}-R$ and $\mathrm{L}\mathrm{u}-R$ results makes possible an estimate of the crystal-field parameters in the pure-rare-earth metals.