Dielectric losses in ferroelectric ceramics produced by domain-wall motion

The oscillation of domain walls caused by alternating fields is often thought to be the origin of dielectric losses. In this paper the physical nature of losses is explained by the damping of moving 90° domain walls. For frequencies up to 108 Hz the origin of damping of the wall motion is ascribed to point defects within the 90° domain wall. At high frequencies damping results from the reflection of thermal-lattice waves impinging on a moving 90° domain wall.