A New Synthetic Route of Strontium Niobates via Sr-Nb Mixed Alkoxides

Abstract

Synthesis of strontium niobates via single crystals of Sr-Nb mixed alkoxides has been attempted in this study. New single crystals of Sr-Nb mixed alkoxides were synthesized by a reaction of Sr(OEt)₂ and Nb(OEt)₅ in ethanol. The composition of Sr_xNb_y etoxides obtained was Sr₂Nb₂, Sr₄Nb₂ and Sr₅Nb₄. By heat treatment at 200~300 degrees C of these Sr-Nb mixed etoxides, Sr₂Nb₂O₇, Sr₄Nb₂O₉ and Sr₅Nb₄O₁₅ were formed according to the atomic ratio of Sr_xNb_y in the alkoxides. The lattice parameters of the strontium niobates heated at 800 degrees C for 1.5h in air were a=0.39nm, b=2.705nm and c=0.454nm for Sr₂Nb₂O₇, a=4.289nm, b=1.167nm and c=1.014nm for Sr₄Nb₂O₉ and a=0.568nm, c=1.137nm for Sr₅Nb₄O₁₅. The crystallite sizes of the strontium niobates were found to be 20~60nm.