Electromechanical Behavior of Single-Crystal Strontium Titanate

Abstract

A study of electrostriction in strontium titanate provides evidence that SrTi${\mathrm{O}}_{3}$ is not perfectly cubic. It exhibits a small but noticeable piezoelectric effect whose temperature and field dependence is $\frac{E}{(T\ensuremath{-}{T}_{a})}$, whereas the electrostrictive effect was found to vary as $\frac{{E}^{2}}{{(T\ensuremath{-}{T}_{c})}^{2}}$. ${T}_{a}$ and ${T}_{c}$ are the temperature of the phase transition (102.5\ifmmode^\circ\else\textdegree\fi{}K) and the Curie temperature (41\ifmmode^\circ\else\textdegree\fi{}K), respectively. The results of an extensive study of the compliance constant ${s}_{11}$ above and below the phase transition are reported and are combined with previously reported data to yield a complete set of elastic coefficients ${c}_{\mathrm{ik}}(T,E)$ or ${s}_{\mathrm{ik}}(T,E)$ as a function of temperature and externally applied electric field $E$. An accurate determination of the transition temperature as a function of electric field provides the basis for a possible check on a recent explanation of the phase transition by Cowley.