摘要
采用提拉法生长4种不同[Li]／[Nb]比（0．94，1．05，1．20，1．38）的Ce（0．1％（质量分数））：Mn（0．05％（质量分数））：LiNb03晶体和掺镁量为5％（摩尔分数）的Mg：Ce（0．1％）：Mn（0．015％）：LiNbO3晶体。测试晶体红外光谱，[Li]／[Nb]为1．2和1．38的Ce：Mn：LiNb03晶体OH吸收峰移到3466cm^-1，这是化学计量比的标志吸收峰。Mg（5％（摩尔分数））Ce：Mn：LiNbO3晶体OH吸收峰移到3535cm^-1，这是Mg^2＋达到阈值浓度的标志吸收峰,以锂空位模型解释OH-吸收峰移动机理。采用光斑畸变法测试晶体抗光损伤能力，采用二波耦合光路测试晶体的指数增益系数、响应时间、计算载流子浓度。随着[Li]／[Nb]比增加，这些数据指标增加。[Li]／[Nb]为1．38，Ce：Mn：LiNbO3晶体是化学计量比，它的指数增益系数比Ce：Mn：LiNbO3晶体提高1倍，响应速度和抗光损伤能力提高1个数量级以上，是性能最为优良的光折变晶体材料之一。
In this paper, four Ce （0.1mass %）：Mn （0.015 mass %）：LiNbO3 crystals with various Li/Nb ratios （0.94, 1.05, 1.20, 1.38） and Mg：Ce （0.1 mass %）：Mn （0.015 mass %）：LiNbO3 crystals with doping Mg^2＋（5 mol %） were grown by Czochralski method. The infrared spectra of the crystals were measured. The results show that the OH absorption peaks of Ce：Mn ： LiNbO3 with Li/Nb ratio of 1.2 and 1.38 shift to 3466cm^-1, which is the marker peak of the stoichiometric LiNbO3. The marker peak at 3535 cm^-1 of MgO threshold value is revealed in Mg（5mol%）. Ce ： Mn ：LiNbO3 crystal. The mechanism of the OH absorption peak was disscussed by the Li-vacancy model. The optical damage resistant properties were measured by faclua-distoritium method. The exponential gain coefficient, the response time and the effect carrier concentration of the crystal were measured by the two-wave coupling experiment. The results show that these measured parameters are increase with the increase of Li/Nb ratio, and the exponential gain coefficient of Ce ： Mn ： LiNbO3 crystal with Li/Nb ratio of 1.38 is two times larger than that of the congruent crystal. In particular, the response time and photodamage resistant ability of stoichiometric Ce ： Mn ： LiNbO3 crystal are one order of magnitude higher than that of other crystals. The stoichiometric Ce ： Mn ： LiNbO3 crystal is an excellent photorefractive material.
出处
《功能材料》
EI
CAS
CSCD
北大核心
2007年第A01期400-403,共4页
Journal of Functional Materials
