CONTROL OF ABNORMAL GRAIN GROWTH AND DIELECTRIC PROPERTIES OF FERROELECTRIC STRONTIUM BARIUM NIOBATE

摘要

Strontium Barium Niobate (SBN) is a tetragonal tungsten bronze structured ferroelectric material. The unusual sintering behavior of SBN exhibits abnormal grain growth, duplex microstructure and low density that has plagued commercial exploitation of SBN. The formation of duplex microstructure becomes more prominent when synthesized by conventional solid-state approach. Although the exact reason of duplex microstructure is not known, it is believed that composition inhomogeneity is one of the reasons of such ambiguity. Will homogeneous mixing will eliminate this problem? To answer this question, coprecipitation a wet chemical route, has been employed for synthesis of SBN; in this route, the precursors are mixed in the molecular level. It is thought that the improved composition uniformity might help in eliminating microstructure related problems with improved dielectric properties. Our findings in this connection on microstructure dielectric and ferroelectric properties are discussed in the manuscript.