Influence of mobility of the 90° domain walls on the effective properties of PbTiO₃ceramics

Using the effective medium method, dielectric, piezoelectric and elastic constants of the PbTiO 3 ceramics have been calculated with the reversible displacement of the 90° domain walls taken into account. It was assumed, in accordance with the purport of the experiment, that the crystallites contained 90° and 180° domains with the latter's concentration depending on the strength of the poling field.