The structural phase transition of ${\mathrm{EuTiO}}_3$ near $T_{\mathrm{S}}$ = 282 K is investigated by temperature- and magnetic-field-dependent measurements of the linear thermal expansion (TE) on a polycrystalline sample. At $T_{\mathrm{S}}$ a distinct anomaly is seen in the linear coefficient which is similar to the anomaly seen at the cubic-to-tetragonal phase transition in ${\mathrm{SrTiO}}_3$. The anomaly is well described by the thermal displacement correlation function which exhibits an abrupt change at the structural phase transition caused by a double-well potential in the oxygen-oxygen interaction. In accordance with previous data a pronounced magnetic-field effect on the TE is observed which might yield an alternative potential for applications.

• Received 2 July 2014
• Revised 21 August 2014

DOI:https://doi.org/10.1103/PhysRevB.90.104105