铟掺杂近化学计量比铌酸锂单晶的缺陷结构

摘要

In order to investigate the occupation mechanism of anti-photo-damage media in the near-stoichiometric LiNbO3 crystals, the near-stoichiometric In:LiNbO3( In:SLN) crystals with different indium contents were grown by the top seed solution growth ( TSSG) method. The defect structure evolution was derived from the X-ray powder dif-fraction, differential thermal analysis ( DTA ) , ultraviolet-visible ( UV ) absorption and infrared ( IR ) spectrum measurement. The analysis implies that the threshold concentration of In2 O3 in near-stoichiometric LiNbO3 crystals was between 1% and 1.5%. The investigation of defect structure indicates that In3+ions first replace Nb4+Li to obtain In2+Li ions when the doping content of In2 O3 is less than the threshold concentration. Conversely, In3+ ions begin to occupy normal Li and Nb sites to obtain In2+Li-In2-Nb compensation structure when the In2 O3 doping content is more than the threshold concentration.%为了探讨抗光损伤介质在近化学计量比铌酸锂晶体中的占位机制,采用顶部籽晶助熔剂方法( TSSG)生长了不同铟含量的近化学计量比铌酸锂( In:SLN)晶体,利用X射线衍射、差热分析,紫外-可见吸收光谱及红外光谱测试并研究了晶体中的缺陷结构变化规律. 分析发现在近化学计量比铌酸锂晶体中,In2 O3的阈值浓度介于1%~1.5%. 缺陷结构研究表明,当In2 O3掺杂量低于阈值浓度时,In3+离子优先取代Nb4+Li ,形成In2+Li离子;当In2 O3掺杂浓度高于阈值浓度时, In3+离子开始同时占据正常的Li与Nb位,形成In2+Li-In2-Nb电荷自补偿结构.