FORMATION OF A SERIES OF BARIUM TUNGSTEN BRONZES.

Article abstract of DOI:10.1016/0022-4596(79)90077-X

The phases occurring in samples of gross composition Ba//xWO//3(0. 01 less than x less than 0. 33) heated at temperatures between 1073 and 1373 degree K have been determined using X-ray diffraction and electron microscopy. At all temperatures a tetragonal tungsten bronze phase with a narrow homogeneity range of x equals 0. 20-0. 21 was observed to form. In addition, at temperatures up to 1273 degree K, a series of orthorhombic intergrowth bronzes forms within a restricted composition range around x equals 0. 04. The latter phases are unstable at higher temperatures and were not found in preparations made at 1323 degree K. Similarly a new type of bronze phase forms at x equals 0. 14-0. 16 at temperatures up to 1323 degree K, but not at 1373 degree K. The structure of this phase is unknown. Aspects of the crystal chemistry of the barium bronzes and the relationships to other bronze phases are discussed.