Crystal-field properties ofYb2Ti2O7usingYb170Mössbauer spectroscopy

Mössbauer spectroscopy has been used to investigate the crystal-field levels of ${\mathrm{Yb}}^{3+}$ in ${\mathrm{Yb}}_2$ ${\mathrm{Ti}}_2$ ${\mathrm{O}}_7$. The hyperfine field observed when an external field is applied provides a local magnetization measurement which has been interpreted in terms of an appropriate crystal-field Hamiltonian. A procedure is described for performing a powder average to include the effects of magnetic anisotropy in the calculations. Combining the current results and previous measurements on isomorphic compounds gives crystal-field values of $B_2^0=15-21\mathrm{}$ K and $\frac{B_4^0}{B_2^0}=0.01\mathrm{}$.