The attenuation of pulsed 10‐megacycle ultrasound in barium titanate ceramics is studied as a function of temperature and applied field. In the region of the coercive field strength attenuation maxima are observed which correlate with a rapid change of the electromechanical response. Both phenomena can be traced to domain wall movements of two different kinds. A model is proposed which identifies one kind of attenuation maximum with a stress equalization in the polarized crystal grains of a ceramic, and the other kind with the nucleation of antiparallel domains. In both cases the losses appear to be caused by an elastic hysteresis due to dislocation movement.

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