Solution‐Precipitation of Fine Powders of Barium Titanate and Strontium Titanate

Abstract

Hydrolytic reactions of metal alkoxides offer a broad range of possibilities for their use in the preparation of ceramic powders. This paper reports a unique and novel process to prepare fine powders of BaTiO 3 and SrTiO 3 from stable precursor solutions by carefully controlling the pH and temperature. This simple route offers good control of stoichiometry and the powders are agglomerate-free with fine particles of size 0.06-0.1 µm and were well sintered at 1200°a nd 1350°C, respectively. The dielectric properties of the dense ceramics are also reported. The formation aspects of these perovskite phases are also discussed.

Percolative BaTiO3–Ni composite nanopowders from alkoxide-mediated synthesis

“…The first one occurs between room temperature up to approximately 400 • C and is attributed to the burnout of organics and the release of physisorbed water on the surface of the BaTiO 3 nanopowders. 25,26 The second weight loss is observed for a wide range of temperatures up to 1000 • C and mainly results from the release of chemisorbed water and/or incorporated hydroxyl ions in the lattice of BaTiO 3 . It is apparent that with the increase of Ni addition, as-prepared BaTiO 3 -Ni nanopowders show increased weight losses due to the higher concentrations of organics, water, and hydroxyl ions.…”

Structural and electrical characteristic of crystalline barium titanate synthesized by low temperature aqueous method

“…However, the conventional method suffers from contamination and grain growth problems during milling and calcinations process, respectively. Thus, there have been many investigations to overcome the limitation of the conventional method using wet chemical method, such as sol-gel method (Pfaff, 1992;Moreno et al, 1995;Kuo and Ling, 1994), Pechini processing (Pechini, 1966;Stockenhuber et al, 1993;Wada et al, 2003) using a citric or oxalate complex as the precursor, hydrothermal synthesis (Dutta and Gregg, 1992;Clark et al, 1999;Moon et al, 1999) and precipitation method (Flaschen, 1955;Kiss et al, 1966;Kumar, 1999). Among many advantages of such wet chemical synthesis are homogeneous mixing at all metal cations at a molecular level and facilitates crystallization with small grain-sized particles at relatively low temperature as compared to classic solid sate reaction.…”

Synthesis and Characterization of Nanocrystalline SrTiO3

“…Various wet-chemical methods have been reported in the literature [22][23][24][25][26][27][28] for the synthesis of SrTiO 3 nanopowders: the polymerized complex (PC) method, the microemulsion method, the hydrothermal synthesis, the stearic acid sol-gel method, the solution-precipitation method, and the combustion synthesis using ethylene diamine tetraacetic acid (EDTA) and NH 3 (aq.). Our experience is that the SrTiO 3 synthesized through solgel techniques suffers from the presence of unavoidable traces of carbon.…”