Synthesis and thermal stability of a new barium polytitanate compound, Ba1.054Ti0.946O2.946

A new barium polytitanate Ba1.054Ti0.946O2.946 was synthesized by a citrate chemical route. The X-ray powder pattern of this compound was indexed to a hexagonal system, with space group P63/mmc and lattice parameters <F>a=5.722</F>(4) and <F>c=13.996(8)</F> A˚. Prolonged annealing of the Ba1.054Ti0.946O2.946 in air at temperatures above 1150°C leads to a peritectoid decomposition reaction yielding Ba2TiO4 and cubic-BaTiO3, consistent with the known phase diagram. A thermal stability study of this compound demonstrates it to be a stable phase under ambient conditions and metastable under low oxygen partial pressures. [ABSTRACT FROM AUTHOR]