Hydrothermal synthesis of acicular lead zirconate titanate (PZT)

The hydrothermal synthesis of lead zirconate titanate (PZT) powder with acicular morphology using organic mineralizer, tetramethylammonium hydroxide pentahydrate (TMAH), has been investigated. The TMAH concentration and reaction time have a pronounced effect on the phase composition and morphology of the resultant powders. At 150 degreesC phase pure PZT was obtained after 24 h in 0.5 m TMAH solution, and after 12 h in 1 m TMAH solution. TMAH concentrations lower than 0.5 m do not produce the PZT phase. At all TMAH concentrations, the appearance of a fibrous intermediate phase, Zr-modified tetragonal PX-phase PbTiO3 is observed at the early stage of the hydrothermal process. Depending on the TMAH concentration, the intermediate either dissolves to form cube-shaped PZT (TMAH concentrations of 1-4 m) or transforms in situ to acicular PZT powder using its fibrous morphology as a template (TMAH concentrations of 0.5-0.75 m). (C) 2001 Elsevier Science B.V. All rights reserved.