摘要
研究了掺镁掺铁铌酸锂晶体的紫外、可见及红外光谱 ,首次发现当掺镁量超过通常所说的阈值 (第一阀值 )时 ,Fe3+ 离子和部分Fe2 + 离子的晶格占位由锂位变为铌位 ,但仍有部分Fe2 + 离子留在锂位 .晶体缺陷化学分析表明 ,继续增加掺镁量 ,占锂位的Fe2 + 离子数将逐渐减少 ;当掺镁量达到另一个适当的值 (第二阀值 )时 ,全部Fe2 + 都占铌位 ,晶体的抗光折变能力空前提高 ,这种现象称作双阈值效应 .
The ultraviolet-visible and infrared absorption spectra of Fe2O3 and MgO co-doped lithium niobate (LiNbO3) crystals were studied. It was found that some Fe2+ ions were still in Li-sites though Fe3+ ions changed their site occupation from Li-sites to Nb-sites while the doping concentration of MgO was above the threshold (the first threshold). Defect chemical analysis shows that the amount of Fe2+ ions will decrease as the doping concentration of Mg increases, and when the doping concentration reaches. a suitable value (the second threshold) all Fe2+ ions in Li-sites will diminish. It is expected that LiNbO3 crystal doped with the second threshold will have an excellent ability to resist laser induced optical damage. This phenomenon is called as double thresholds effect.
出处
《红外与毫米波学报》
SCIE
EI
CAS
CSCD
北大核心
2003年第1期40-44,共5页
Journal of Infrared and Millimeter Waves
基金
国家自然科学基金 (批准号 6 0 10 80 0 1
10 1740 40 )资助项目~~
关键词
掺镁
铌酸锂晶体
抗光折变
微观机理
吸收光谱
双阈值效应
Mg doped lithium niobate crystal
anti-photorefraction
micro-mechanism
absorption spectra
