ABSTRACTDuring the past decades the solid state chemistry of tellurium oxides has been enriched by a series of quaternary metallates. Interest attaches not only to the chemical and physical properties of these compounds, but also to their structure, which have been studied by modern methods. The partial similarity of earth alkaline metals and lead in solid state chemistry and their relationships in oxides opens a wide field of investigations. Eight new compounds in the systems Ba-M-Te-O (M= Nb, Ta) and Pb-M-Te-O (M = Mn, Ni, Cu, Zn) were prepared and structurally characterized: Ba2Nb2TeO10, Ba2M6Te2O21 (M = Nb, Ta) and the lead compounds PbMnTeO3, Pb3Ni4.5Te2.5O15, PbCu3TeO7, PbZn4SiTeO10 and the mixed compound PbMn2Ni6Te3O18. The structures of all compounds are based on frameworks of edge and corner sharing oxygen octahedra of the transition metal and the tellurium. Various different channel structures were observed and distinguished. The compounds were prepared by heating from mixtures of the oxides, and the single crystals were grown by flux method or solid state reactions on air. The synthesis conditions were modified to obtained microcrystalline material for purification and structural characterizations, which were carried out using a variety of tools including powder diffraction data and refinements of X-ray data. Relationships between lead transition metal tellurium oxides and the earth alkaline transition metals tellurium oxides are compared.
Electronic Phenomena of Transition Metal Oxides