Averaging by Relaxation and the Dynamic Jahn-Teller Effect

Abstract

Averaging effects produced by relaxation have been observed for Sr${\mathrm{Cl}}_2$: ${\mathrm{La}}^{2+}$, a system exhibiting the dynamic Jahn-Teller effect. Observed temperature and sample dependences are consequences of a rapid direct relaxation process between the vibronic components of the ${}_{}{}^2{}_{}{}^{}E$ ground state. This interpretation is consistent with similar effects seen for ${\mathrm{Cu}}^{2+}$, ${\mathrm{Sc}}^{2+}$, and ${\mathrm{Eu}}^{2+}$ in cubic crystals.