Coercive field in fine-grained plzt ceramics

Principally the polarization reversal in ferroelectric ceramics with tetragonal symmetry can be derived from 90° or 180° domain reorientations, in ceramics with rhombohedral symmetry it involves 71° and 109° or 180° domain reorientations. Especially the PLZT system contains certain ceramics characterized by predominating 71° and 109° processes. For these materials the coercive field is calculated by means of the domain wall pressure involved from the internal stress state of the ceramics. Measurements of the coercive field of fine-grained (mean grain size 1-2 μm), lanthanum-doped lead zirconate-titanate ceramics (PLZT) of the composition 6/65/35 are consistent with the requirements of the reported theory.