Figure A1.

Measured relative dielectric constants versus field obtained from differentiation of the P – E loop (${\mathit{\epsilon }}_{PE}\left(meas\right)$) and from C – V measurements (${\mathit{\epsilon }}_{CV}\left(meas\right)$). The calculated curves follow from the model for the rotation (${\mathit{\epsilon }}_{33}^{rot}$) and switching (${\mathit{\epsilon }}_{33}^{sw}$) branches of the P – E loop. (a) (001)-oriented PMN-PT device. (b) (110)-oriented device.