Preparation and characterisation of the compounds sodium tetraoxoniobate(V) Na3NbO4 and sodium tetraoxotantalate(V) Na3TaO4

Abstract

The preparation is described of two forms of the ternary oxide Na₃TaO₄ which are analogous to cubic and monoclinic forms of the compound Na₃NbO₄. A third orthorhombic form of each compound has been prepared by the reaction of sodium oxide with the transition metal under controlled conditions. The cubic form of the compound Na₃TaO₄ has been prepared as a single phase and the relationship of this phase to the monoclinic and orthorhombic forms is discussed.