Crystallization behavior in a low temperature acetate process for perovskite PbTiO3, Pb(Zr, Ti)O3, and (Pb1−x, Lax) (Zry, Ti1−y)1−x/4O3 bulk powders

Abstract

An aqueous, metallo-organic precursor for PbTiO₃ (PT), Pb(Zr, Ti)O₃ (PZT), and (Pb_1−x, La_x) (Zr_y, Ti_1−y)_1−x/4O₃ (PLZT) ceramic powders has been developed employing the acetate complexes of Pb²⁺, La³⁺, Zr⁴⁺, and Ti⁴⁺. The crystallization behavior (e.g., degree of crystallization and crystallite size) was examined over the temperature range of 400–700 °C with concentrations of excess lead varying from 0–5% using x-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy techniques. It was found that PT, PZT, and PLZT crystallize at temperatures as low as 450 °C, 500 °C, and 500 °C, respectively, and the excess lead required for crystallization of the perovskite phase is ⋚1%. Intermolecular mixing among acetate precursors via chelating and bridging structures was evident and appeared to be responsible for the low crystallization temperatures. The process is compared to the current sol-gel methods for its possible use in thin film ferroelectric manufacture.