SINGLE CRYSTAL GROWTH OF NEW SOLID SOLUTIONS AND THEIR FUNCTIONAL PROPERTIES

点击翻译按钮获取中文摘要

It has been impossible to estimate the ionic conductivity of the solid solutions of the scandium tungstate structure with trivalent cations whose ionic radii are greatly different, because they cannot be synthesized in a polycrystalline form. In this study, various types of single crystals for the aluminum tungstate-rare earth tungstate solid solutions were synthesized by the Czochralski (CZ) method.The obtained aluminum tungstate-lutetium tungstate solid solutions were transparent and had a satisfactory quality. The structures of the single crystals were confirmed to be the scandium tungstate structure from the X-ray powder diffraction analysis and existence both of aluminum and rare earth was also clarified by electron probe microanalysis (EPMA) measurements.The aluminum tungstate-lutetium tungstate single crystal was also synthesized by the electrical injection of lutetium ions into aluminum tungstate. The obtained crystals were as much as those grown by the Czochralski (CZ) method. In addition, aluminum tungstate europium tungstate single crystal could be synthesized in a similar way.The lattice constants of these single crystals increased by the substitution with the larger rare earth ions. Aluminum ion conducting behaviors were greatly enhanced by the rare earth doping because of the increase in their lattice constants, especially along c-axis.