Low-temperature anomaly of the elastic modulus in Tb2Ti2O7
Mamsurova L. G., Pigal'skii K. S., Pukhov K. K.
The elastic modulus in Tb2Ti207 decreases appreciably at low temperatures. The electron-strain interaction and the particular features of the structure of the lower-lying energy levels of a Tb3+ ion in the crystal field of the Tb2Ti207 lattice are responsible for this effect. The critical temperature of the cooperative Jahn-Teller transition in Tb2Ti207 is estimated to be Tc ~ 0.1 K.