Syntheisis and Characterization of Bismuth Tungstate Crystals by Solution Growth Technique

摘要

Growth of ferroelectric Bi{sub}2WO{sub}6 (BWO) mono-domain bulk crystals was attempted by the vertical-Bridgman (VB) method below the phase transition (ferro- to paraelectric) temperature of 940°C using Li{sub}2B{sub}4O{sub}7 as a flux. In this method, Pt crucibles with different shapes were used. The crucible with a wedged tip bottom produced BWO crystal with a thickness of over 4 mm along the crystallographic c-axis (perpendicular to the spontaneous polarization axis). Using BWO mono-domain crystals grown by slow cooling technique, on the other hand, their electric properties were characterized. The dielectric constants, ε{sub}(ij), and electromechanical coupling factor, k{sub}33, of the crystals were 70-100 and 36% at room temperature, respectively.