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本文采用液相法合成了高纯度磺基水杨酸锶(简称SSS)多晶粉末原料,并采用热分析、红外光谱和XRD分析对多晶粉末原料进行表征。以水为溶剂分别在不同pH值下(pH=2.50、1.50和0.60)进行了SSS结晶习性实验。结果表明,在水溶液中当pH=0.60时SSS结晶性最好,实验还测定了SSS晶体在不同pH值溶液中的溶解度曲线,并进行了过饱和溶液成核机理的研究。研究结果表明,当生长溶液pH为0.60时,控制单晶生长温度在40~50℃区间,采用水溶液降温法可生长出63 mm×25 mm×3 mm的透明单晶。 相似文献
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通过测定不同温度下HgI2在浓度分别为0.25 mol/L,0.50 mol/L,0.75 mol/L,1.00 mol/L的KI水溶液中的溶解度,绘制了溶解度曲线.结果表明:KI水溶液浓度一定时,温度对HgI2在KI溶液中的溶解度影响很小;温度一定时,随着KI水溶液浓度增大,HgI2的溶解度大幅度增大;随着KI水溶液浓度的增大,温度对HgI2在KI水溶液中的溶解度变化的影响增大.根据所得到的HgI2-KI-H2O体系性质,选取1.00 mol/L的KI水溶液溶解碘化汞,通过缓慢降温,利用顶部籽晶法生长碘化汞晶体,得到了重达17.4 g的鲜红透明的晶体. 相似文献
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以NH_4SCN和 CdCl_2·2H_2O为反应原料,采用缓慢降温法,从水溶液中生长了尺寸为:10 mm×7 mm×4 mm新的化合物Cd(SCN)Cl单晶体; 采用元素分析、红外光谱、EDS、TG/DTA、粉末X射线衍射和单晶X射线衍射对所生长的晶体进行了表征.结果表明:所得晶体分子式为:Cd(SCN)Cl,属于斜方晶系Pnma空间群,晶胞参数为a=0.95967(7) nm, b=0.42595(3) nm, c=1.01789(7) nm, V=0.41608(5) nm~3,Z=4.热分析结果表明,晶体在190 ℃时具有良好的物理化学稳定性并且热分解的最终残留物是CdS.采用重量分析法测定了化合物Cd(SCN)Cl在不同温度条件下的溶解度.采用维氏显微硬度法对该晶体的力学性能进行了研究,其硬度值为78.6 kg/mm~2. 相似文献
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在溶液填充度f=70;,温度T=400,450,500和550℃的条件下,本实验通过淬冷失重法测定了KTP晶体在K2HPO4+KH2PO4水溶液中的溶解度.结果发现:在温度T≥450℃,K2HPO4和KH2PO4的浓度分别为2 mol/1和0.1 mol/1的条件下,KIP晶体在溶液中有足够大的溶解度和溶解度温度系数.该结果符合水热法生长KTP晶体的要求.并且通过水热法在溶液填充度f=70;,温度T=470~520℃的条件下,以2mol/1 K2HPO4+0.1 mol/1KH2PO4+1;质量分数H2 O2为矿化剂,合成出尺寸为24×14×60 mm3的KTP晶体. 相似文献
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紫外非线性光学晶体三硼酸铯的生长和性能 总被引:3,自引:3,他引:0
采用泡生法和提拉法生长出三硼酸铯(化学式CsB3O5,简称CBO)晶体,研究了晶体生长工艺条件及晶体生长形态.泡生法生长的CBO晶体的尺寸为40mm×25mm×25mm;生长过程中晶体转速为10~20r/min,降温速率为0.1~0.2℃/d.用提拉法生长出20mm×30mm的CBO晶体;生长过程中液面温度梯度为60℃/cm,提拉速度为8mm/d.在生长过程中Cs2O的挥发速度大于B2O3的挥发速度.CBO单晶的晶面由[011]斜方柱和[010]斜方柱单形组成,属于[011]单形是4个较大的面,属于[101]单形是4个较小的三角形晶面.CBO在紫外波段具有较大的有效非线性光学系数.利用CBO进行Nd∶YAG激光和频获得了高转换率的波长355nm及266nm相干光输出. 相似文献
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In the current paper we designed a simple glucose reduction route for synthesis of sheet‐like Cu dendrites on a high yield, using CuSO4 as the starting material. The reaction was carried out at 180 °C for 18 h in the absence of any structure‐directing agent. The product was characterized by X‐ray powder diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and electron diffraction (ED). Some factors influencing the shapes of Cu microcrystals, including the reaction temperature, time, and the concentration of the starting CuSO4, were investigated. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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Xinxin Zhuang Genbo Su Guofu Wang Guohui Li Zixiang Huang 《Crystal Research and Technology》2004,39(9):754-758
A new crystalline complex zinc nickel sulfate heptahydrate (ZNSH) has been prepared. The crystal structure was investigated by x‐ray single crystal diffraction method and the empirical formula is Zn0.24Ni0.76(SO4)·7H2O. The ZNSH crystal belongs to the orthorhombic space group P212121 with cell parameters a = 6.7742(14) Å, b = 11.748(2) Å, c = 12.009(2) Å. The deep‐green ZNSH single crystal with dimension of 30 × 25 × 25 mm3 has been grown by the cooling solution method. The constituent ratio of ZNSH crystal grown from various compounding solutions at temperature range 40‐50 °C is approximate invariant. The crystal absorption spectra with theoretical analysis are reported. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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The growth morphology of crystals is analysed from macroscopic point of view and the recent developments in this field are surveyed. In particular, it is shown that, for specific geometry characterized by interfacial angles a given face can increase in size for a very wide range of relative growth rates and need not be the slow‐growing face. Even growing faster than the neighbouring faces, such a face can increase in its size. However, there are other faces with other specific geometry, which can decrease the size growing more slowly than one of the neighbouring faces. If the growth time is sufficiently long, such a face may disappear and not be represented in the final crystal morphology. In the present survey the concepts given earlier [5] are extended. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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P. Di Martino R. Censi L. Malaj D. Capsoni V. Massarotti S. Martelli 《Crystal Research and Technology》2007,42(8):800-806
In the present study, metronidazole was crystallized in several solvents, according to both the “cooling crystallization” and the “crystallization by non‐solvent addition”. Particle properties, such as crystal habit, elongation ratio, and mean particle size, were determined by SEM analysis. Structural changes and development of polymorphic forms were excluded by both Differential Scanning Calorimetry (DSC) and X‐Ray Powder Diffractometry (XRPD). Crystal habit (and thus elongation ratio) was typically influenced by both the solvent polarity index and the crystallization method: solvents with higher polarity index tended to promote acicular or stick‐shaped crystals with a high elongation ratio, while isodimensional crystals were promoted by decreasing the polarity index, as was particle aggregation. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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晶体美丽有用,构造和谐有序。光电功能晶体可实现光能和电能的相互转化,在微电子、光电子、通信、航天及现代军事技术等高科技领域占有重要地位。人类认识晶体,源于天然矿物。从矿物晶体的发现到光电功能晶体的人工生长和应用经历了漫长的发展,晶体种类、晶体质量、生长理论、生长技术以及应用等方面均取得了较大进展。本文简述了从矿物宝石到晶体学发展的历程,介绍了压电晶体、电光晶体、激光晶体、非线性光学晶体和闪烁晶体等几类光电功能晶体发展历程及晶体生长研究的进展,展望了未来光电功能晶体的发展趋势。 相似文献
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晶体形态一些基本概念的实际意义分析 总被引:5,自引:1,他引:4
本文对晶体学中关于晶体形态一些古老的基本概念(单形的正形与负形、左形与右形、一般形与特殊形)进行了深入思考,并从实际晶体形态上发育这些单形的角度,分析了它们的本质区别与内在含义:单形的正形与负形是属于同一几何单形、同一对称型(点群)的两个结晶单形,它们可以相聚;单形的左形与右形也是属于同一几何单形、同一对称型(点群)的两个结晶单形,但它们却具有不同的内部结构,所以它们不能够相聚;单形的一般形与特殊形只有结晶单形意义,无几何单形意义.这些认识阐明了过去我们多年来并没有足够重视的一些理论与实际问题,这有助于晶体形态对称理论的发展,也有助于晶体学教学思路的明确. 相似文献