Synthesis and electrical characterization of Li0.30Ca0.35TaO3 perovskite synthesized via a polymerized complex route
Journal of Solid State Chemistry, Volume 178, Issue 6, June 2005, Pages 1915-1924
Quoc Nghi Pham, Murugesan Vijayakumar, Claude Bohnke, Odile Bohnke
Abstract
The synthesis of Li0.30Ca0.35TaO3 perovskite by a Pechini-type polymerizable precursor method is carefully described. The thermal decomposition of the precursor and the formation of a pure perovskite phase were investigated by means of differential thermal analysis–thermogravimetric analysis (DTA–TGA) and XRD techniques. A pure and well-crystallized phase has been obtained at a lower temperature and with a much shorter synthesis time than the phase obtained by conventional solid-state reaction method. The morphology of the powder after heating at 1300 °C was observed by laser granulometry, Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). Impedance spectroscopy data allowed us to determine the electrical properties, i.e., permittivity and dc-conductivity, of the bulk and grain boundaries. The results are discussed on the assumption of the brick layer model.