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High-quality KTiOPO4 (KTP) crystals were grown by a top seeded solution growth (TSSG) method using K8P6O19–BaF2 as a flux. The volatility of different solvents, such as K8P6O19 (K8), K8–NaF, K8–KF, and K8–BaF2, was measured. These fluoride additives in K8 fluxes and their compositional effects on the growth of KTP crystals were studied and discussed. The transmissivity and optical homogeneity of KTP crystals were also measured. 相似文献
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The effect of growth method (solution or gel growth) and growth conditions on the morphology of ice analogue crystals (sodium fluorosilicate) has been studied. Many habits typical for atmospheric ice crystals (hexagonal columns, plates, different types of stars or dendrites) were obtained during experiments. The dependence of growth rate of basal and prism faces of columnar crystals on supersaturation was measured for crystals growing by evaporation of solvent. The experiments establish evaporation rate and growth rate ranges at which appearance of certain types of crystals is most probable. The experiments have also shown that good quality sodium fluorosilicate crystals can be obtained in TMS gel. These crystals were significantly bigger than those obtained in solution. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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利用X射线衍射和显微激光拉曼光谱研究熔盐法自发结晶的KTP晶体、顶部籽晶熔盐法KTP晶体和水热法KTP晶体的晶胞参数和拉曼光谱特征,分析和比较不同方法生长的KTP晶体的晶体结构与化学键特征峰.研究表明:KTP晶体的晶胞参数与晶体生长方法有关,熔盐法自发结晶的KTP晶体生长过程中降温速率较快,晶胞体积相对较小;熔盐法和水热法KTP晶体中部分拉曼特征峰的位置因生长方法不同呈现一定的差异,水热法KTP晶体在782 cm-1、744 cm-1和515 cm-1处出现的特征峰可视为水热法KTP晶体的标志峰,借此可将其与熔盐法晶体相区分. 相似文献
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You-Jun Fu Zhang-Shou Gao Xun Sun Shen-Lai Wang Yi-ping Li Hong Zeng Jian-Ping Luo Ai-Dong Duan Ji-Yang Wang 《Progress in Crystal Growth and Characterization of Materials》2000,40(1-4):211-220
The synthesis of KDP from its raw material has been found exist in the growth solution. In the crystal growth experiment, significant extension of specific faces was observed at low dopant concentration. At high doping concentration, the growth rate of the whole crystal decreased with no significant habit modification. The inhibiting effects of phosphite and other H-bonding anionic ions on the growth of pyramidal faces are discussed. Rapid growth rate experiments have been carried out with purified material and an averaged growth rate of 18.6mm/day was obtained. 相似文献
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I. Bhaumik S. Ganesamoorthy R. Bhatt A. K. Karnal R. Sundar V. K. Wadhawan 《Crystal Research and Technology》2006,41(12):1180-1183
The presence of an impurity like rhodium in the platinum crucible used for the growth of KTiOPO4 (KTP) single crystals can have severe consequences in the performance of devices made from these crystals. In the present study the effect of rhodium incorporation has been investigated. Rhodium‐incorporated KTP crystals have a lower ionic conductivity (1.3 × 10–7 S/cm at 100 kHz) than pure KTP crystals (3.5 × 10–6 S/cm at 100 kHz) along the c‐axis. And the optical absorption in the green‐wavelength regime leads to a detrimental effect on their SHG performance. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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Igor V. Zatovsky Nikolay S. Slobodyanik V. I. Ivanenko Yu. S. Oseledchik V. Yu. Letsenko Tetiana I. Ushchapivska 《Crystal Research and Technology》2016,51(2):178-182
Solid solutions KTi1‐XHfXOPO4 (х = 0.008 – 0.107) possessing the KTiOPO4 structure, have been synthesized in molten system K2O‐P2O5‐TiO2‐HfF4. The crystal growth experiment of Hf‐doped KTP crystal has been reported. The X‐ray powder diffraction data and chemical analysis are also presented. It has been shown that KTiOPO4 crystal structure slightly changes when Hf incorporates into the framework. Transmission/absorption spectra of KTi0.974Hf0.026OPO4 crystals have been recorded. The incorporation of Hf ions shifts the optical absorption edge in the UV‐visible spectrum towards the long‐wavelength region with absorption near 387 nm. 相似文献
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使用优级纯的NH4H2PO4(含量>99.5;)和重水(纯度>99.5;)为原料,在重水中经过三次氘化重结晶,获得含氘量>95;的结晶原料.上述DADP晶体作为原料配成1000ml的饱和溶液,用降温转动法生长出22mm×23mm×78mm尺寸的透明大晶体,并且测定其晶体结构、透过光谱和激光损伤阈值.从数据分析来看在最重要的光谱应用波段(1.06μm附近)DADP晶体综合性能是很优越的,这使得DADP有利于作为电光晶体材料和制作高频高灵敏度的电光器件. 相似文献
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Xu Jiayue Fan Shiji Lin Yafang Xu Xuewut 《Progress in Crystal Growth and Characterization of Materials》2000,40(1-4):137-144
Transparent KLN crystals 10mm in diameter and 25 to 45mm in length have been grown by the modified vertical Bridgman technique from different melts in the range of 3035mol% K2O, 1723mol% Li2O and 4350mol% Nb2O5. The growth conditions are a growth rate of less than 0.25 mm/hr, temperature gradient in solid-liquid interface of 23 °C/mm and growth direction of <110>. As-grown KLN crystals have tetragonal tungsten bronze structure. Most of the as-grown crystals do not crack when cooling through the paraelectric/ferroelectric phase transition. 180° domain structures are observed after the KLN crystal was etched in boiling 2HNO3:Hf. Dielectric properties and transmission spectrum of the as-grown KLN crystals are measured. 相似文献
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A simple solution phase approach using dimethyl formamide (DMF) as solvent is utilized to obtain selenium (Se) microcrystals. Different morphological modifications of the products result from varied reaction environments. Solvothermal treatment of Se with DMF in an autoclave at 170°C yields rod‐like, and feather‐shaped microcrystalline structures while reduction of selenium dioxaide (SeO2) by DMF generates microspheres at 30°C and 80°C, rods admixed with spherical particles at 120°C and predominantly micro rods at 150°C. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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采用Czochralski方法生长出了Yb0.140Gd0.813La0.047VO4晶体,并测试了Yb3+与La3+在GdVO4晶体中的有效分凝系数.实验结果表明,掺入La3+可在一定程度上提高晶体的激光损伤阈值和晶体生长过程中的稳定性.此外,La3+的引入还有利于减缓高浓度Yb3+掺杂晶体中的荧光捕获效应和浓度猝灭效应的激光损伤阈值.Yb3+在该晶体中具有很宽的吸收半峰宽和荧光半峰宽,分别为26nm和47nm,具有较大的吸收截面和发射截面,分别为2.26×10-20cm2和0.96×10-20cm2,因此该晶体有望用作可调谐激光晶体和飞秒激光晶体. 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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Yu. Velikhov I. Pritula I. Ganina M. Kolybayeva V. Puzikov A. N. Levchenko 《Crystal Research and Technology》2007,42(1):27-33
Potassium dihydrogen phosphate (KDP) crystals doped with xylenol orange (XO) and methylthymol blue (MTB) are grown from aqueous solutions by the method of solvent evaporation at room temperature under the conditions of natural convection and by the method of temperature lowering. Studied is the influence of the mother solution acidity on the character of the crystal coloration. The color and coloration intensity of the grown crystals are shown to strongly depend on the solution's pH. It is revealed that the crystal habit changes in the presence of organic dyes. The optical transmission spectra and the luminescence spectra of KDP:XO solutions and of the grown crystals are measured. The effect of thermal treatment and UV‐irradiation on the coloration stability of the crystals is studied. It is found that the laser damage threshold in the prismatic impurity rich colored sectors of KDP:XO is the same as that in the prismatic sectors of pure KDP crystals. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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M. Arivanandhan K. Sankaranarayanan K. Ramamoorthy C. Sanjeeviraja P. Ramasamy 《Crystal Research and Technology》2004,39(8):692-698
In order to grow benzophenone single crystal, an organic nonlinear optical material, a cost‐effective Vertical Bridgman‐Stockbarger system has been designed and fabricated by employing a two‐zone, transparent furnace made out of immiscible liquids. Transparent, optical quality benzophenone single crystals were successfully grown as a result of a suitable thermal gradient achieved by means of introducing an intermediate liquid in between the two immiscible liquids. The effect of change in the volume of the intermediate liquid thereby the thermal gradient on the growth parameters was analyzed. The quality of the grown single crystal was justified using X‐ray powder diffraction analysis, FTIR, TG‐DTA and optical transmission studies. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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KTP crystals have been grown by two nucleation techniques namely spontaneous nucleation in flux medium and nucleation on Pt rod using K6P4O13 flux.10 °C/h, 7 °C/h, 0.8 °C/h, 0.4 °C/h and 0.2 °C/h cooling rates were applied for spontaneous nucleation and crystals up to 15 × 7 × 4 mm3 in size were grown. 1 °C/h and 0.8 °C/h cooling rates were also used for nucleation on Pt rod and crystals up to 8 × 6 × 3 mm3 in size were grown. The effect of cooling rate on size, morphology and optical quality of grown crystals by both techniques were studied. For nucleation on Pt rod upper and lower rotation rates limits and an optimum rotation rate were distinguished for each cooling rate. Quality of the grown crystals by both techniques was characterized by optical transmission analysis. 相似文献
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Numerical simulation of the LEC-growth of GaAs crystals with account of high-pressure gas convection
The influence of the inert gas pressure on the growth of 4 GaAs crystals by the liquid encapsulated Czochralski method (LEC) process is studied for a range of the Ar gas pressure up to 10 bar by using our finite-volume computer code STHAMAS. Up to the pressure of 0.6 bar we are considering laminar convection. For the pressure range from 5 to 10 bar we are using the buoyancy extended standard k-ε turbulence model with wall functions to simulate the gas flow. The numerical results show that the Argon gas pressure has a strong influence on the consumption of heater power in qualitative agreement with our experimental results. The convex curvature of the growth interface and the maximum thermal stress (von Mises criterion) are found to increase with increasing gas pressure both in the laminar and turbulent evaluations. 相似文献