Preparation of barium titanyl oxalate tetrahydrate for conversion to barium titanate of high purity

Abstract

A procedure is described for preparing barium titanyl oxalate tet rahydrate, BaTiO (Cz0 4h4 HzO, in which the mole ratio of TiOz to BaO is unity. To achi eve this ratio the alt must be precipitated from solutions that do not contain sodium, potassium, or ammonium ions.Ignition of barium titanyl oxalate tetrahydrate produces barium titanate, BaTi03• To prepare barium titanate free of strontium, the barium chloride used must be specially purified.

Aerosol Processing of Materials

“…This approach has been used extensively for liquid-phase routes. Mixed-metal alkoxides, oxalates or citrates have been extensively used for the synthesis of multicomponent glasses and oxides (titanates) (Clabaugh et al, 1956;Kiss et al, 1966;Mazdiyasni and Brown, 1970;Dislich, 1971;Hennings and Mayr, 1978;Bradley, 1989;Gupta and Cooper, 1989;Ma et al, 1991). However, there are fewer reports of the use of mixed-metal precursors for gas-phase synthesis of multicomponent materials.…”

Annealing effects on the crystallite size and dielectric properties of ultrafine Ba1−xSrxTiO3(0 < x < 1) powders synthesized through an oxalate-complex precursor

“…In the last decade, solution-based approaches have become popular for the preparation of nanocrystalline BaTiO 3 (BTO) and its strontiumdoped derivatives (BSTO) because of their major advantages over the conventional solid state reactions, namely the high homogeneity and easy control of the particle size/chemical composition of the resulting nanopowders, as well as much lower synthesis temperatures. Thus, BaTiO 3 nanoparticles were synthesized by various aqueous approaches, such as sol-gel, [1][2][3][4] hydrothermal, [5][6][7][8][9] microwave heating, [10][11][12] coprecipitation, 13,14 microemulsion 15 and thermal decomposition of mixed oxalates, 16,17 peroxides 18-20 and citrates. 21,22 However, the use of aqueous-based chemistry for the synthesis of nanocrystalline BaTiO 3 and its strontium-doped derivatives is often hampered by the limited availability of water-soluble Ti precursors as well as the high sensitivity of titanium precursors towards hydrolysis.…”

Preparation of barium strontium titanate powder from citrate precursor

“…11 The method involves dissolving alkoxides of titanium and barium in organic solvent and adding water at appropriate temperatures to hydrolyse these alkoxides to precipitate the mixed oxides. The reaction can be described by Eqn [4] The shortcomings of this approach are chemical instability of the metal alkoxides, the complexity of the process and the high cost. Therefore this method is unsuitable for mass production.…”

“…Among them the hydrolysis of metal alkoxide 1 , oxalate precipitation in ethanol 2 , and alcoholic dehydration of citrate solution 3 are among the more attractive methods. In 1956 Clabaugh et al 4 described the preparation of barium titanyl oxalate tetrahydrate for conversion to high-purity barium titanate. Kudaka et al 5 also prepared stoichiometric barium titanyl oxalate tetrahydrate.…”