摘要:
LuTaO4是最高密度的闪烁体基质,研究它的结构及其相变对单晶制备具有指导意义.用固相法制备了Lu2O3和Ta2O5摩尔比为1：1时在不同温度下形成的多晶粉末,用X射线衍射及Rietveld全谱拟合研究了多晶粉末的物相和结构.结果表明, Lu2O3： Ta2O5摩尔比为1：1的样品在1740?C时合成的物相为M′-LuTaO4,在1800?C时为M′-LuTaO4和M-LuTaO4的混合物,在1840?C时全部转变为M-LuTaO4.当温度升高到2058?C时,样品呈熔融状态,对淬火得到的样品进行结构精修,给出了M-LuTaO4, Lu3TaO7和Ta2O5的晶胞和原子坐标参数,它们的重量比分别占78.1%,18.9%和3.0%.这些结果为制备以LuTaO4为基质的高密度闪烁体单晶具有参考价值.
Abstract:
Since LuTaO4 is a scintillator host with the highest density, it is important to investigate the structure and phase transition for its single crystal preparation. The polycrystalline formed by the mixture of Lu2O3:Ta2O5 with the molar ratio 1 : 1 is prepared by solid state reaction method at different temperatures. The phase transitions and structures of the polycrystalline powders are investigated by X-ray diffraction and Rietveld refinement. The results show that the polycrystalline has a single phase M′-LuTaO4 when sample is prepared at 1740 ?C, it presents a mixture phase of M′-LuTaO4 and M-LuTaO4 at 1800 ?C, and it displays a single phase M-LuTaO4 at 1840 ?C. The sample is melted when the calcined temperature is 2058 ?C, the melt is quenched and the polycrystalline is the mixture of M-LuTaO4, Lu3TaO7 and Ta2O5 , whose structural parameters, including the lattice parameters, atomic fraction coordinates, etc. are obtained by Rietveld refinement to their X-ray diffraction pattern, and the results show their weight ratios are 78.1%, 18.9%and 3.0%, respectively. These results are valuable for the single crystal growth of the heavy scintillators with the host LuTaO4.
首页
登录
注册
下载: