Hyperfine Interactions and Paramagnetic Relaxation of Dysprosium Ions in DyCrO3

Mössbauer experiments on ${\mathrm{Dy}}^{161}$ in DyCr${\mathrm{O}}_3$ are reported. At 4.2°K the paramagnetic hyperfine pattern was found to be consistent with the following interactions for the ground state of ${\mathrm{Dy}}^{161}$: $g_0{\beta }_N{H}_{\mathrm{eff}}=-806\mathrm{}\pm 20$ Mc/sec and $\frac{1}{4}{e}^{2}qQ=420\mathrm{}\pm 20$ Mc/sec. The dysprosium spin relaxation times are $\tau \left(20\mathrm{}°\mathrm{K}\right)\le 7\times {10}^{-9\mathrm{}}$ sec and $\tau \left(78\mathrm{}°\mathrm{K}\right)\ge 5\times {10}^{-11\mathrm{}}$ sec. The crystal-field constant ${V_2}^0$ was estimated to be 159 ${\mathrm{cm}}^{-1\mathrm{}}$.