  We used an optical reflection method to measure the temperature-dependence of
the piezoelectricity, electrostriction and time constant of a morphotropic
phase boundary (MPB) thin film. We obtained the piezoelectric constant and the
electrostrictive constant as a function of temperature by curve fitting the
experimental data. We also obtained the time constant as a function of
temperature and applied voltage. An abnormal behavior of the strain that was
larger at 275 K than at 285 K was observed. This observation was also
consistent with the minimal hysteresis behavior of the time constant at 275 K.
We provided a possible explanation for this observation.
