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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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为了采用扩散法制备大厚度近化学计量比钽酸锂(nSLT)晶体,本文从富锂多晶料配比及合成工艺、极化工艺和扩散条件等方面对钽酸锂晶体高温富锂扩散工艺进行了研究,对处理后晶片组分、畴反转电压和光学均匀性进行了表征,研究了扩散条件对晶体组分的影响.结果表明,富锂多晶料锂钽为60/40时较佳,多次使用对所制备晶片组分、畴反转电压和光学质量无明显影响.在研究基础上,制备了系列nSLT晶片,晶片厚度最大为3.2 mm,其组分达到化学计量比且组分均匀,矫顽场约为152 V/mm,晶体光学质量满足实用需求. 相似文献
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研究了扩散法制备近化学计量比铌酸锂晶体的工艺,从原料配比、合成方式、晶片放置方式和扩散工艺等方面进行了工艺优化.对不同厚度和切割方向的铌酸锂晶体进行扩散处理,对三英寸Z-cut铌酸锂晶体进行了批量扩散试验,并对扩散后的晶体进行了组分和均匀性测试.结果表明,厚度为3.1 mm的Z-cut晶体组分达到近化学计量比,光学质量达到实用化要求,而XYZ=5.1 mm×5.1 mm×21.0 mm的晶体光学质量较差,同时厚度达1.8mm的Z-cut三英寸近化学计量比铌酸锂晶片可实现批量制备. 相似文献
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通过生长一系列掺钼近化学计量比铌酸锂晶体,研究了晶体的光折变性能,发现在488 nm和532 nm波长辐照下,当Mo的掺入量为0.5mol;时,晶体的光折变灵敏度分别达到0.25 cm/J和0.21 cm/J.此外,极化条件的改变可以缩短晶体在488 nm波长辐照下的光折变响应时间.通过红外光谱、紫外可见吸收光谱和X射线光电子能谱的测试,对掺钼近化学计量比铌酸锂晶体的光折变性能变化的机制进行了研究. 相似文献
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声表面波用压电晶体的新进展 总被引:1,自引:1,他引:0
报道了我们在Li2B4O7、Sr3Ga2Ge4O14、LiNbO3、LiTaO3等声表面波用压电晶体材料方面的最新研究进展.采用改进型坩埚下降法成功生长了直径3~4英寸的Li2B4O7晶体,并实现了批量生产.作为硅酸镓镧系列新型压电晶体之一,Sr3Ga2Ge4O14晶体具有最大的压电系数.报道了直径2英寸Sr3Ga2Ge4O14晶体的生长结果,测试了该晶体的压电性能.在CO2(90;)、H2(10;)混合气氛中,分别在700℃和450℃下对LN和LT晶片进行化学还原处理,成功制备了3英寸LN和LT低静电黑片,不仅减少了器件制作工序,而且使成品率提高了5~8百分点.此外,在密封坩埚中生长了低静电LiNbO3晶体,观察到一些新的现象. 相似文献
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Crystallography Reports - The nuclear magnetic resonance (NMR) of 7Li and 6Li nuclei in a LiTaO3 single crystal sample of congruent composition has been experimentally investigated. It is found... 相似文献
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晶体材料的设计与模拟 总被引:1,自引:0,他引:1
从化学反应热力学和动力学的角度出发,系统地分析和计算了一些具有代表性的功能晶体材料的生长、结构与性能.研究结果表明,晶体组成化学键的微观参量可以很好地计算、分析及预测其非线性光学倍频效应、生长特性及缺陷控制等宏观物理化学特征.因此,化学键方法与模型可以帮助我们实现光电功能晶体材料的结构设计与模拟、性能预测与模拟等晶体工程领域的研究目标.该工作可以为物理、化学、化工及材料等领域的相关研究提供很好的研究思路. 相似文献
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超宽禁带半导体材料金刚石在热导率、载流子迁移率和击穿场强等方面表现出优异的性质,在功率电子学领域具有广阔的应用前景。实现p型和n型导电是制备金刚石半导体器件的基础要求,其中p型金刚石的发展较为成熟,主流的掺杂元素是硼,但在高掺杂时存在空穴迁移率迅速下降的问题;n型金刚石目前主流的掺杂元素是磷,还存在杂质能级深、电离能较大的问题,以及掺杂之后金刚石晶体中的缺陷造成载流子浓度和迁移率都比较低,电阻率难以达到器件的要求。因此制备高质量的p型和n型金刚石成为研究者关注的焦点。本文主要介绍金刚石独特的物理性质,概述化学气相沉积法和离子注入法实现金刚石掺杂的基本原理和参数指标,进而回顾两种方法进行单晶金刚石薄膜p型和n型掺杂的研究进展,系统总结了其面临的问题并对未来方向进行了展望。 相似文献
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《Liquid Crystals Today》2013,22(2)
Abstract The foundation of a new company ROLIC has been recently announced, which is a spin-off from the Liquid Crystal Group of F. Hoffmann-La Roche Ltd. ROLIC will develop new liquid crystal devices, and will provide electronics manufacturers with new generations of products, as well as designing and developing new functional organic materials in prototype quantities to support device development. 相似文献
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Shiwen Shu Dabin YuYan Wang Feng WangZirong Wang Wu Zhong 《Journal of Crystal Growth》2010,312(21):3111-3116
This paper reports on the thermal-induced performance of hexagonal metastable In2O3 nanocrystals involving in phase transition and assembly, with particular emphasis on the assembly for the preparation of functional materials. For In2O3 nanocrystals, the metastable phase was found to be thermally unstable and transform to cubic phase when temperature was higher than 600 °C, accompanied by assembly as well as evolution of optical properties, but the two polymorphs coexisted at the temperature ranging from 600 to 900 °C, during which the content of product phase and crystal size gradually increased upon increasing temperature. The assembly of In2O3 nanocrystals can be developed to fabricate In2O3 functional materials, such as various ceramic materials, or even desired nano- or micro-structures, by using metastable In2O3 nanocrystals as precursors or building blocks. The electrical resistivity of In2O3 conductive film fabricated by a hot-pressing route was as low as 3.72×10−3 Ω cm, close to that of In2O3 single crystal, which is important for In2O3 that is always used as conductive materials. The findings should be of importance for both the wide applications of In2O3 in optical and electronic devices and theoretical investigations on crystal structures. 相似文献
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We analyze angular bandwidths of extrema of the indicative surfaces describing spatial anisotropy of piezoelectric (PE) and electrooptic (EO) properties of doped lithium niobate (LiNbO3:MgO) and langasite (La3Ga5SiO14) crystals. A number of highly efficient experimental geometries are suggested, which are promising for PE and EO devices. Our data obtained with both analytical and numerical techniques characterize angular stability of those devices and, in particular, their angular aperture. We show that, besides of a maximal size of the electric field‐induced effects, ‘nondirect crystal cuts’ offer considerably higher angular stability of their characteristics, when compared with that typical for ‘direct crystal cuts’ usually employed in PE and EO devices. 相似文献
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F. A. Fernández L. Seddon R. James S. E. Day S. Bulja P. Deo 《Molecular Crystals and Liquid Crystals》2015,619(1):19-27
Liquid crystal substrates have been shown to provide the means to develop low-cost, reconfigurable, adaptive and tuneable microwave devices for mobile and wireless communication systems. In order to take maximum advantage of the possibilities that these materials offer and to design LC-based devices appropriately, techniques for the characterisation of the liquid crystal dielectric properties are needed. Similarly, appropriate modelling methods are required to simulate accurately the switching behaviour of the liquid crystal and the characteristics of the wave propagation through the devices, taking full consideration of the point-by-point variation of the material tensor permittivity. 相似文献
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有机半导体单晶由于具有内部长程有序的分子排列结构、缺陷及晶界少等优点,表现出优异的光电性能,是实现有机半导体器件实用化的一种重要材料。目前,研究者们已经发展出多种可应用于有机单晶的生长方法,其中,微距升华法是一种可以在大气环境下采用蒸镀的方式制备有机微/纳单晶的方法。然而,当将这种方法应用于C8-BTBT时发现,由于分子的熔点较低,蒸镀得到的是分子直接从液态凝固为无定形/多晶的结构。在本工作中,通过使用溶剂蒸汽退火的方式对其进行后处理,成功地将这种无定形/多晶结构转化为分立的单晶。为了表征所得到的晶体形貌和结构,分别使用光学显微镜、X射线衍射和原子力显微镜等仪器对其进行了表征,发现所制备的晶体结构具备单晶的典型特征。 相似文献