Synthesis and structural determination of alkali and alkaline earth metal containing bismuth vanadates.

摘要

Exploratory synthesis plays an important role in the quest to discover new materials. There are very few structurally characterized alkali metal containing bismuth vanadates. Hybridization of the 6s and 6p orbitals of Bi 3+ and the resulting lone electron pair yields some very interesting stereochemistry and steric related properties. Some of those properties include ferroelectricity, ferroelasticity, electronic and ionic conduction, superconductivity, nonlinear optical capabilities and selective catalysis.; Systematic exploration of the Na-Bi-V ternary system produced a new phase of NaBi₃V₂O₁₀. This material crystallizes in the P1¯ space group and the reported oxygen ion conductivity is apparently due to the presence of interstitial oxygen rather than oxygen vacancies.; Stabilization of the tetragonal scheelite phase of BiVO₄ has been achieved by the substitution of a M2+ for Bi3+ . This has not been accomplished previously by a M2+ cation substitution. The compound Ca_0.29Bi_0.71VO _3.855 crystallizes in the P4¯ space group.; An investigation of the K-Bi-V ternary system resulted in the discovery of a new potassium vanadate. K₁₀Bi₄V₄O ₂₁ crystallizes in the P6¯ space group with a equal to 10.205(2)Å and c equal to 7.669(2)Å.; Other new compounds prepared, for which structures have not been determined are α-Na₃BiV₂O₈, β-Na₃BiV ₂O₈, K₈Bi₅V₅O₂₄, Rb₂BiVO₅, a rubidium compound with a 3:3:2 stoichiometric ratio of Rb:Bi:V, a rubidium compound with 2:1:1, a sodium compound with 2:1:1 and a lithium compound with a 1:1:1 stoichiometric ratio of Li:Bi:V.