Synthesis and powder x-ray diffraction studies of novel compounds related to beta alumina and magnetoplumbite

Abstract

X-Ray powder diffraction techniques coupled with bond valence analysis were used to provide a description of new magnetoplumbite-type materials synthesized in an effort to determine the extent to which the unusual chemistry observed in BaGa12O19 depends on composition, size and identity of the trivalent cation present. The new materials synthesized in this study are BaAl3V9O10, BaFe3V9O19, BaFe3Nb9O19, BaV12O19, BaAl2.5V9.5F9.5N9.5 and BaMg1.33Ta10.33N19. Results of the examination of these compounds using X-ray powder diffraction methods are presented, and show that the only compounds prepared in which the unusual chemistry of BaGa12O19 is observed are BaAl3V9O19, BaFe3V9O19 and BaAl2.5V9.5F9.5N9.5. The results of a detailed examination of bond lengths and valences of a nitride and mixed nitride-fluoride compound are also presented to predict whether or not nitride and nitride-fluoride analogs to magnetoplumbite-like oxdes exists.