Synthesis of Functional Inorganic Materials such as Doped Barium Titanate, Vanadate Compound Phosphors, and Fluorine-doped Lithium Aluminate

Abstract

This article introduces the synthetic methods adopted by the author in the preparation of Ho-doped BaTiO₃, vanadate compound phosphors, and a phosphor host material of fluorine-doped lithium aluminate, including the solution method, the self-flux method, and the precipitation method. The solution method had the advantages of compositional uniformity in the precursor on the atomic scale and easy introduction of Ho³⁺ into the perovskite type BaTiO₃ crystal structure. The self-flux method is a method of preparing the product phases using a starting material that forms a melt during the heat treatment, allowing the growth of crystalline grains. The incorporation of flux components in the products sometimes yielded rather unusual materials. The precipitation method was specifically effective for the ‍preparation of vanadate compound phosphors such as Ba₂V₂O₇ and Zn₃(VO₄)₂, in which insoluble salts of vanadate ions and cations such as Ba²⁺ and Zn²⁺ were precipitated in aqueous solution with a fixed composition depending on solution pH.