Thermodynamic theory of the lead zirconate-titanate solid solution system, part I: Phenomenology

Abstract

Compositions within the lead zirconate-titanate (PZT) solid solution system have been extensively used in polycrystalline ceramic form in a wide range of piezoelectric transducer applications. However, the growth of good quality PZT single crystals for compositions across the entire phase diagram has not been accomplished. Due to the lack of single-crystal data, an understanding of the properties of polycrystalline PZT has been limited. If the single domain (intrinsic) properties of PZT could be determined, then the extrinsic contributions (e.g. domain wall and defect motions) to the polycrystalline properties could be separated from the intrinsic contributions. The purpose of this research has been to develop a thermodynamic phenomenological theory to model the phase transitions and single-domain properties of the PZT system. This paper is the first of a series of five papers describing the thermodynamic theory of PZT that has been developed for the entire solid solution system. In this paper the previous work that led to the present theory will first be reviewed, followed by the presentation of the energy function for PZT, and the solutions and property relations that can be derived from this energy function.