近化学计量比LiNbO_3晶体的生长及其组分测定  

Growth of Near-stoichiometric LiNbO_3 Crystal and Composition Determination

作　　者：陈晓军[1] 李兵[1] 朱登松[1] 李冠告[1] 陈绍林[1] 黄自恒[1] 吴仲康[1] 

机构地区：[1]南开大学物理科学学院,天津300071

出　　处：《人工晶体学报》2001年第2期129-134,共6页Journal of Synthetic Crystals

基　　金：国家自然科学基金 (No .6 990 80 0 30 ) ;国家 86 3计划 (NO .86 3 715 0 0 1 0 10 2 ) ;973计划 (No .19990 330 0 4)资助项目

摘　　要：铌酸锂晶体 (LiNbO3)是一种典型的非化学计量比晶体 ,通常所使用的同成分LiNbO3晶体中的锂铌比 ([Li]/ [Nb])约为 4 8.6 / 51.4。我们利用提拉法 ,从掺入 11mol%k2 O的同成分LiNbO3熔体中生长出了高光学质量的近化学计量比LiNbO3单晶。与同成分LiNbO3晶体相比 ,其吸收边向短波方向移动 ;E模 (153cm- 1)喇曼谱线宽从 9.4cm- 1降低到了 7.0cm- 1,A1模 (876cm- 1)喇曼谱线宽从 2 5.5cm- 1降低到了 2 0 .0cm- 1;产生 532nm～ 10 6 4nm 2次谐波的相匹配温度从室温增加到了155.5℃ ;OH- 红外吸收谱线宽明显变窄 ,波形也有明显的变化。这些结果表明这种LiNbO3晶体中的LiO2 含量为 4 9.6mol% ,即 [Li]/ [Nb]为 0 .984 ,接近其化学计量比。Lithium niobate(LiNbO 3) crystal is a kind of typical non stoichiometric crystal,and generally used one is congruent crystal with [Li]/[Nb] ratio of about 48.6/51.4.In this paper,we report that near stoichiometric LiNbO 3 crystal is grown with Czochralski method from a congruent melt with addition of 11mol% K 2O.In comparison with congruent one,the position of absorption edge moves to short wave,Ramam linewidth decreases from 9.4cm -1 to 7.0cm -1 for the E mode(153cm -1 ) and from 25.5cm -1 to 20.0cm -1 for the A1 mode (876cm -1 ).Its phase matching temperature for 1064 532nm second harmonic generation increases from room temperature to 155.5℃ and its OH - infrared absorption band is changed distinctly in shape.The linewidth also becomes greatly narrower.According to these measurements,the lithium oxide content in crystal can be estimated to be about 49.6mol%,which is closed to the ideal stoichiometry of LiNbO 3 crystal.

关 键 词：铌酸锂晶体 化学计量比 晶体生长 组分 测定 

分 类 号：O782[理学—晶体学]