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在铌酸锂(LiNbO3,LN)中掺入摩尔分数为0.1;的CeO2,以提拉法从不同[Li]/[Nb]摩尔比([Li]/[Nb]=0.750,0.850,0.946,1.100)的熔体中生长出了Ce:LN晶体.测试了晶体的晶格常数、红外光谱和居里温度.结果表明:随着[Li]/[Nb]比的增加,晶体仍为三方的LN晶体,且晶格常数和晶胞体积没有发生大的变化,v(OH-)振动峰的位置依次向长波方向移动,居里温度依次增加,结构缺陷减少.由于Ce和[Li]/[Nb]比的协同作用,[Li]/[Nb]比为1.100的Ce:LN晶体已接近化学计量比,[Li]/[Nb]比为0.850的Ce:LN晶体的居里温度近似等于纯LN晶体.利用二波耦合光路测试了晶体的衍射效率、写入时间和擦除时间,计算了晶体的光折变灵敏度及动态范围.测试了晶体的抗光致散射能力,结果表明:[Li]/[Nb]比越高的Ce:LN晶体的光折变性能越好.并分析了不同[Li]/[Nb]比Ce:LN晶体光折变性能增强的机理. 相似文献
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近化学计量比掺镁铌酸锂晶体的抗光折变性能 总被引:3,自引:0,他引:3
应用气相传输平衡技术,我们获得了3种近化学计量比掺镁铌酸锂晶体,晶体的掺镁量接近我们以前提出的第二阈值.在我们实验室所能达到的最大光强26 MW/cm2照射下,在所有近化学计量比掺镁铌酸锂晶片中没有观察到光斑畸变,该光强比同成分铌酸锂晶体所能承受的光强高6个量级,为目前已报道的铌酸锂晶体之最.应用双光束全息写入法测得掺1.0 mol; Mg近化学计量比铌酸锂晶体的光折变饱和值仅有4.6×10-7,比同成分铌酸锂晶体小两个量级,从已有实验数据推测,该晶体的抗光折变能力应当比同成分铌酸锂晶体高9个量级以上. 相似文献
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助熔剂提拉法生长化学计量比LiNbO3晶体 总被引:5,自引:2,他引:3
利用助熔剂提拉法,分别从掺入11mol;K2O的同成份LiNbO3熔体中和从掺入19mol;*!K2O的化学配比LiNbO3熔体中生长出高质量近化学计量比LiNbO3单晶.对这两种从不同配比熔体中生长的晶体进行光谱分析表明,与同成份比LiNbO3相比较,其紫外吸收边出现明显蓝移,OH红外吸收峰的位置和线宽也都有显著的变化.室温极化反转测试显示,两种晶体的矫顽场分别为4.4kV/mm和0.8kV/mm.根据所得测量结果,估计两种晶体中Li2O的含量分别为49.6mol;和49.9mol;.其中从掺19mol; K2O化学配比LiNbO3熔体中生长出的LiNbO3单晶的Li2O含量已非常接近50mol;的化学配比.进一步优化生长工艺,获得成份均匀、大尺寸化学计量比晶体的工作正在进行中. 相似文献
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在LiNbO3晶体中掺进0.1wt?O2和0.03wt?2O3以Czochralski技术生长不同Li/Nb比(0.94、1.20、1.40)Ce:Fe:LiNbO3晶体,其中Li/Nb=1.40的Ce:Fe:LiNbO3晶体是化学计量比.测试了不同Li/Nb比Ce:Fe:LiNbO3晶体抗光损伤能力,得到随着Li/Nb比的增加,晶体的抗光损伤能力增加.研究了晶体抗光损伤能力增强的机理.随着Li/Nb比的增加,晶体的响应速度和光折变灵敏度增加.测试不同Li/Nb比Ce:Fe:LiNbO3晶体位相共轭效应,利用产生的位相共轭光波消除图像的位相共轭畸变.利用Li/Nb=1.40的Ce:Fe:LiNbO3晶体做记录介质,Li/Nb=1.20的Ce:Fe:LiNbO3晶体作位相共轭镜进行全息关联存储实验.实验结果表明,存储系统具有实时处理,成像质量好,信噪比高和可反复使用的优点. 相似文献
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为利用中子散射技术更好地研究铌酸锂晶体的结构缺陷,以Nb2O5和同位素的7LiOH为原料,采用提拉法从58.5;的7Li熔体中成功生长了近化学计量比的同位素7LiNbO3晶体.晶体质量约为35 g,室温下晶体密度为4.634g/cm3,采用差热热重(DTA/TG)分析仪测得晶体熔点为1223℃,在室温至1250℃范围内晶体重量未发生变化.室温下晶体在500~3200 nm波段平均透过率达74;,OH-吸收峰位置在2877 nm,利用紫外吸收边法测得晶体中7Li含量为49.46;.在633 nm波长下,利用c切晶片,测得晶体的折射率为No=2.2872,ne=2.1909. 相似文献
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研究了高温富锂气氛下锂离子在低掺镁铌酸锂晶体中的扩散.采用气相输运平衡法制备了掺杂1mol; MgO的不同锂含量的铌酸锂(Mg1LN)晶体,采用热分析仪测试了晶体的居里温度.制备了一系列不同锂含量的Mg1LN多晶料,拟合了晶体锂含量与居里温度的关系.采用Boltzmann-Matano法求解了扩散方程.结果表明,扩散温度为1100 ℃时,Mg1LN晶体中锂离子扩散系数为3.2×10-9~13.0×10-9 cm2/s,当扩散温度为1145 ℃时锂离子扩散系数约是1100 ℃时扩散系数的三倍.因此,适当提高扩散温度是提高气相输运平衡法制备近化学计量比低掺镁铌酸锂晶体效率的有效办法. 相似文献
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Palatnikov M. N. Sidorov N. V. Kadetova A. V. Aljoshina L. A. Teplyakova N. A. Biryukova I. V. Makarova O. V. 《Crystallography Reports》2020,65(1):18-26
Crystallography Reports - A comparative study of the optical and structural homogeneity of a LiNbO3 crystal with a congruent composition and LiNbO3 : ZnО ([ZnО]... 相似文献
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SrCeO3:Sm3+红色发光粉的制备及发光性能 总被引:2,自引:0,他引:2
采用溶胶-凝胶法合成了SrCeO3∶Sm3+红色荧光粉,用XRD、SEM、FL分析表征了样品的结构、形貌及发光性能。研究了助熔剂H3BO3对其发光性能的影响。结果表明:样品为具有正交晶系结构的SrCeO3晶型,呈椭球型结构。荧光光谱测试结果表明:Sm3+掺杂的SrCeO3在紫外波段有两个吸收带,一是峰值位于320 nm左右的宽吸收带,归属于Ce4+→O2-的电荷迁移带,另一个为峰值位于408 nm的锐线吸收带,对应于Sm3+的6H5/2→4L13/2跃迁吸收;在波长408 nm的激发下,样品发红光,发射主峰位于601 nm,对应于Sm3+的4G5/2→6H7/2跃迁。样品的发光强度随着Sm3+和助熔剂H3BO3加入量的增加先增强,后减弱。当Sm3+的掺杂量为3mol%,H3BO3加入量为0.5 mol%时,发光强度最大。 相似文献
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Y. Zheng E. Shi S. Wang Z. Lu S. Cui L. Wang W. Zhong 《Crystal Research and Technology》2004,39(5):387-395
Stoichiometric lithium niobate single crystals with different Li contents have been grown both by the top‐seeded solution growth (TSSG) method from potassium containing flux and by the double crucible Czochralski (DC Cz) method. Spectroscopic properties (e.g. the UV absorption edge, Raman linewidth) and the Curie temperature measurement have been used for the characterization of the crystal composition. The double crucible Czochralski method is found to be suitable for mass production of stoichiometric LiNbO3 with Li content larger than 49.7 mol% and homogeneity of 0.03 mol%. The domain structures and etching morphologies on negative and positive c‐surface were also investigated by chemical etching method. A new domain structure of three‐fold symmetric sectors were observed in near‐stoichiometric LiNbO3 grown by TSSG method. The straight line arrangement hillocks on negative c‐surface and the net‐like arrangement etch lines were observed and explained by stress etching mechanism. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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以K_2O为助熔剂,应用坩埚下降法生长出了Co~(2+) 初始浓度为0.5 mol;,以及ZnO分别为3 mol;与6 mol;的单掺与双掺杂SLN晶体(分别用SLN0, SLN3, SLN6表示).测定了晶体上下部位的吸收与发射光谱.在晶体的吸收光谱中均可观察到520 nm,549 nm,612 nm,1447 nm四个吸收峰,表明Co~(2+)处于晶体的八面体场中.ZnO的掺入明显地改变了吸收峰的相对强度.在520 nm光的激发下,观察到776 nm的荧光发射,其荧光强度的相对强弱也与ZnO的掺杂量有明显的联系.从吸收边带估算出SLN0, SLN3, SLN6晶体中Li2O的含量分别为49.06 mol;,49.28 mol;, 49.10 mol;.ZnO的掺杂量对Co~(2+)在铌酸锂晶体中的浓度分布有很大的影响作用,当ZnO的掺入量为3 mol;时,明显地抑制了Co~(2+)在LiNbO_3晶体中的掺入,当ZnO掺杂量达到6 mol;时,抑制作用减弱.本文从Zn~(2+)在LiNbO_3中随浓度变化的分凝情况以及对Co~(2+)的排斥作用解释了Co~(2+)在晶体中的分布特性以及光谱的变化情况. 相似文献
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Liang Sun Fengyun Guo Qiang Lv Haitao Yu Hongtao Li Wei Cai Yuheng Xu Liancheng Zhao 《Crystal Research and Technology》2007,42(11):1117-1122
Zr: LiNbO3 crystals has been grown. The crystal composition and phase are analyzed by X‐ray diffration. The optical damage resistance ability of Zr: LiNbO3 crystals is studied by the Sénarmont compensation method and the transmitted beam pattern distortion method. The saturated value of the birefringence change of 6 mol% Zr: LiNbO3 crystal is 1.01×10‐4, which is seven times smaller than that of congruent pure LiNbO3 crystal. The results of UV‐Visible and IR absorption spectra of Zr: LiNbO3 crystals powerfully confirm that the optical damage resistance threshold concentration of the Zr4+ ions doped in LiNbO3 crystals is about 6 mol% in the melt. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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S. H. Yao X. B. Hu J. Y. Wang H. Liu L. Gao X. F. Cheng X. Yin X. F. Chen 《Crystal Research and Technology》2007,42(2):114-118
A near stoichiometric LiNbO3 single crystal has been grown by the Czochralski method from a 58.5% Li melt hold in a large platinum crucible. High resolution X‐ray rocking curves of 30 0 and 0006 reflections indicated that the near stoichiometric LiNbO3 crystal possesses the high structural quality. Compared with the congruent LiNbO3, the near stoichiometric LiNbO3 possesses shorter ultraviolet absorption edge, thus higher Li concentration. The OH– infrared absorption band analyses showed that the Li concentration in the near stoichiometric LiNbO3 crystal is higher than that in the congruent LiNbO3 crystal. This result is in good agreement with that of the ultraviolet absorption edge. The electro‐optic (EO) coefficient γ22 of the near stoichiometric LiNbO3 crystal was measured to be 6.75 pm/V higher than that of congruent LiNbO3 crystal. It also proves the near stoichiometric LiNbO3 electro‐optic Q‐switched requires a low driving voltage and it is advantageous for the device performance. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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D. L. Sun Y. Hang L. H. Zhang G. Z. Luo S. N. Zhu P. K. Lim W. W. Hung 《Crystal Research and Technology》2004,39(6):511-515
Two kinds of near‐stoichiometric LiNbO3 crystals (SLN11 and SLN19) were grown by a flux pulling method from stoichiometric melt with addition of 11mol%K2O and 19mol%K2O, respectively. Compared with the congruent melting LiNbO3, the ultraviolet absorption edges of two crystals shift towards shorter wavelengths, and the locations of the OH‐ infrared absorption band have obvious change and the bandwidths become greatly narrower. From these experimental results, the Li2O contents are determined indirectly to be about 49.6mol% for SLN11 and 49.9mol% for SLN19, respectively. The Li2O content in SLN19 is very close to the ideal value of 50mol%. The coercive fields of two crystals were measured by the poling method at room temperature. A linear relationship between the Li2O content and the coercive field was fitted. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献