Preparation and dielectric study of high-quality PLZT x/65/35 (x = 6,7,8) ferroelectric ceramics

Ferroelectric ceramics are an important class of solid-state materials as they exhibit a wide range of applications. Various compositions of the ferroelectric ceramic (Pb, La)(Zr, Ti)O3 (known as PLZT) were prepared and their dielectric properties were studied. It is difficult to prepare phase-pure PLZT compounds by the direct solid-state reaction method. Its preparation required the use of a special 'covering method' adopted to facilitate phase formation using the solid-state reaction method. High-quality PLZT samples of different compositions (x/65/35, x = 6, 7, 8) prepared using the 'covering method' without adding any excess PbO (to avoid PbO loss) resulted in single-phase formation. The 8/65/35 composition has yielded a dielectric constant of 11273 at TC, which is in good agreement with the literature value [1,2]. Also, as the lanthanum content x was varied from 6 to 8 mole %, TC decreased and the low-frequency (1 kHz) room-temperature dielectric constant value increased. The present publication gives a detailed account of the evolution of the phase-pure PLZT compositions and their physical properties.