Ti：LiAlO2新型晶体的结构分析

通过研究提拉法生长的掺杂Ti浓度为0.2at%的LiAlO2晶体吸收光谱,荧光光谱和红外光谱,来分析此新型晶体的结构.分析发现光谱中仅出现了四价Ti离子的196nm的特征吸收峰,用235nm光激发得到384nm的特征发射峰;针对吸收光谱中660-820nm出现的四个弱小吸收峰提出了一个色心模型,从而解释了空气和富Li气氛处理后吸收峰消失的现象;对比纯LiAlO2晶体的红外光谱发现,Ti的掺入仅影响了[AlO4]键强,而[LiO4]及相关键强几乎不变;结合ICP测试估算出直径50mm,厚1mm的Ti：LiA

The structure of novel LAlO2 crystal with Ti concentration of 0.2 at% was studied by measuring the absorption, luminescence and IR spectra. It was found that the crystal has the 196nm typical quarivalent Ti absorption peak, and also the 384nm typical quarivalent Ti emission peak when excited by 235nm light. A color-center model successfully explains the four small peaks in the range of 660-820nm, which disappeared when the samples were annealed in air or Li-rich atmosphere. Compared to the pure LiAlO2, we can find that the intensity and situation of [LiO4] are unchanged. Combined with the ICP results, we can count the number of Li vacancies to be about 5.5 x 10(20) for the Ti: LiAlO2 with dimensions of phi 50mm x 1 mm.