Study on Single Crystal Growth by Solid State Recrystallization using Defect Sulfide Spinel Compounds

研究了用固态再结晶法生长银或铜缺陷硫化物尖晶石大单晶的方法。这些硫化物尖晶石化合物由于电子和离子混合导体的存在，在固态中具有较大的原子输运。本研究的目的是阐明银或铜缺陷硫化尖晶石的缺陷尖晶石化合物的固态再结晶和生长单晶的机理。采用水平Bridgman法和高温连续退火法制备了正常硫化物尖晶石MIn_5S_8 （M=Cu,Ag）单晶和缺陷尖晶石MIn_7S_<11>、MIn_9S_<14>、MIn_<11>、MIn_< 17>、MIn_<21>、MIn_< 32>单晶。这种方法是一种适合生长具有不同液相线和固相线的大单晶的方法。用x射线衍射法对晶体结构进行了分析。随着单元胞中缺陷空位数的增加，Cu-In-S系列和Ag-In-S系列的晶格常数分别线性增大和减小。用x射线光电子能谱（XPS）分析了Cu、Ag和In离子的价态。Cu和Ag为+1价，In为+3价。通过固气反应，测定了金属原子在固体状态下的化学扩散系数。随着空位数量的增加，其化学扩散系数增大。

Solid state recrystallization method to grow large single crystal of silver or copper defect sulfide spinel compounds was studied. These sulfide spinel compounds have large atomic transport through solid state because of electronic and ionic mixed conductors.The purpose of this study was to clarify the mechanism of the solid state recrystallization and grow single crystal of defect spinel compounds of silver or copper defect sulfide spinel.Single crystals of normal sulfide spinel, MIn_5S_8 (M=Cu,Ag) and defect spinels, MIn_7S_<11>, MIn_9S_<14>, MIn_<11>S_<17> and MIn_<21>S_<32> were grown by a horizontal Bridgman method and successive annealing at high temperature. This method is a suitable way to grow large single crystals, which have different liquidus and solidus.The crystal structures were analyzed by a X-ray diffraction method. According to the increment of the number of defect vacancy in the unit cell, lattice constants of Cu-In-S series and Ag-In-S series were linearly increased and decreased respectively.X-ray Photoelectron Spectroscopy (XPS) is used to analyze the valence of Cu, Ag and In ions. Cu and Ag take +1 valence and In takes +3 valence.By a solid-vapor reaction, chemical diffusion coefficients of metallic atom in solid state were determined. With increasing the number of vacancies, chemical diffusion coefficient of them increase.