共查询到19条相似文献,搜索用时 343 毫秒
1.
2.
3.
相比传统KDP晶体同心旋转的生长方式,本文利用数值模拟的方法,针对不同旋转半径和不同籽晶摆放方式对KDP晶体生长过程中溶液流动和物质输运的影响进行研究,以寻找提高晶体表面过饱和度及其均匀性的方法.计算结果表明:随着旋转半径从0 cm增大到3 cm,晶面时均过饱和度整体也逐渐增大,柱面平均均方差逐渐减小,锥面平均均方差先增大后减小;当晶体摆放方式采用棱边迎流时,晶体表面时均过饱和度相比柱面迎流略有下降,但其平均均方差最小,有利于减少包裹体的产生. 相似文献
4.
5.
6.
7.
采用溶液降温与旋转籽晶相结合的方法培育出不同浓度L-丝氨酸(L-serine)掺杂的KDP单晶,通过粉末X射线衍射、傅立叶变换红外光谱、UV-Vis光谱及热分析(热重/热差)等方法对生长的KDP晶体进行了表征,较系统的分析了不同浓度L-丝氨酸掺杂对KDP的光学以及热稳定性能的影响.研究结果表明:L-丝氨酸掺杂可以提高KDP的透光强度,随着掺杂浓度的增加KDP晶体的光学透过率趋于恒定;L-丝氨酸掺杂对KDP晶体的热稳定性没有显著影响. 相似文献
8.
大尺寸KDP(KH2PO4)晶体在切割过程中容易出现开裂现象,为了研究大尺寸KDP晶体切割过程中开裂机制并提出合理切割方案,本文对大尺寸KDP晶体切削效应进行了研究.大尺寸KDP晶体切削过程中刀片与晶体之间的接触应力和切割引起的热应力是晶体切削过程中主要致裂因素,因此本文采用有限元计算方法对KDP晶体切削过程进行热力耦合数值仿真模拟.结果表明切割过程中KDP晶体与刀片之间的压力应小于4.1 MPa,切口处温差应控制在4.2℃之内,同时本文还得到了切削过程可控参数(车床推进力和刀片的线速度)的安全取值范围,该范围的提出对KDP晶体的切割技术具有十分重要的意义. 相似文献
9.
10.
离子束作用下KDP晶体表面粗糙度研究 总被引:1,自引:0,他引:1
为了避免传统加工过程对KDP( Potassium dihydrogen phosphate)晶体表面产生损伤、嵌入杂质等降低晶体抗激光损伤阈值的不利因素,文章探索采用离子束抛光技术实现KDP晶体的加工.本文主要分析了离子束抛光作用下KDP晶体表面粗糙度的演变过程,采用垂直入射和倾斜45°入射两种方式研究KDP晶体表面粗糙度,利用倾斜45°入射的加工方式提高了KDP晶体的表面质量,其表面均方根粗糙度值由初始的3.07 nm减小到了1.95 nm,实验结果验证了离子束抛光加工KDP晶体的可行性. 相似文献
11.
Single crystals of calcium iodate, monohydrate [Ca(IO3)2, H2O] have been grown by gel technique. Prismatic, prismatic pyramidal, needle shaped and hopper crystals were obtained. These crystals were also grown by doping impurities such as copper and iron. Kinetics of growth parameters was investigated. Structural analysis was carried out by using X‐ray powder diffraction method. Microtopographical study of the habit faces, such as prismatic and pyramidal, of as grown crystals was carried out. Some surface structures are reported. These crystals were etched by various etchants and appropriate etchant is reported. 相似文献
12.
Fafu Liu Mingxia Xu Baoan Liu Lisong Zhang Chengwei Wen Guangai Sun Xun Sun 《Crystal Research and Technology》2016,51(11):681-687
The homogeneity of deuterium distribution in potassium dideuterium phosphate single crystals was studied by Raman and infrared spectroscopy analyses. Results indicated that the pyramidal section exhibited more homogeneous deuterium distribution than the prismatic section. Supersaturation slightly affected the deuterium homogeneity in the pyramidal section of crystals grown rapidly from 80% deuterated solution. Deuterium homogeneity in the prismatic section decreased with increasing supersaturation level of the growth solution. 相似文献
13.
Guozong Zheng Genbo Su Xinxin Zhuang Guohui Li Jiancheng Wang Zhengdong Li 《Crystal Research and Technology》2010,45(2):145-148
KDP crystals were rapidly grown from solutions doped with different Nd3+ concentrations. During the growth process, “foggy” inclusions were selectively captured in the pyramidal sector of KDP crystal and hourglass shaped crystals were obtained. It is found that the nonuniform distribution of Nd3+ ions causes remarkable differences in optical quality between prismatic and pyramidal sectors. With increasing Nd3+ concentration, the optical quality is greatly decreased for pyramidal sectors, while the change is not so obvious for prismatic sectors. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
14.
A. P. Voronov G. N. Babenko V. M. Puzikov A. D. Roshal’ V. I. Salo 《Crystallography Reports》2008,53(4):708-712
The features of doping of KDP crystals with cerium ions and organocerium complexes with alizarin complexon and arsenazo III have been investigated. It is established that “direct” doping by introducing cerium salts into the initial solution cannot be implemented. The effect of organometallic complexes of cerium on the crystal growth has been studied. Organocerium complexes predominantly enter the prismatic or pyramidal growth sectors. It is shown that the complex arsenazo III + Ce blocks the growth of the prismatic sector. Cerium-doped KDP crystals exhibit a photoluminescence band peaking at the wavelength λmax= 350 nm. 相似文献
15.
16.
S. L. Wang Z. S. Gao Y. J. Fu A. D. Duan X. Sun C. S. Fang X. Q. Wang 《Crystal Research and Technology》2003,38(11):941-945
Highly‐deuterated potassium dihydrogen phosphate (DKDP) crystals were grown rapidly from point seeds under high supersaturation in a temperature range of 40‐60 °C. The growth rate was about 1‐2 order of magnitude higher than that of the traditional temperature reduction method. It was found that highly pure raw materials, overheating at high temperature, ultrafine filtration and supersaturation stability were needed to keep the solution from spontaneous nucleation at high overcooling. The effect of growth conditions on pyramid faces was different from that of prismatic faces. The tetragonal to monoclinic phase solubility transition scarcely occurred in our experiments even though the overcooling of monoclinic phase was as high as 10 °C in some cases. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
17.
L. F. Malakhova A. E. Voloshin C. C. Wilson E. B. Rudneva N. G. Furmanova V. I. Simonov 《Crystallography Reports》2003,48(1):29-34
The structures of two crystalline specimens cut out from the pyramidal and prismatic growth sectors of a K(H0.052D0.948)2PO4 single crystal have been studied by diffuse neutron scattering and precision diffuse X-ray scattering. Diffuse scattering is concentrated in the vicinity of the Bragg reflections and is practically the same in specimens cut out from different growth sectors of a single crystal. X-ray diffraction analysis using the extinction parameters provided the establishment of a higher perfection of the specimen cut out from the prismatic growth sector. The precision X-ray studies revealed different configurations of hydrogen bonds in the specimens. 相似文献
18.
L. F. Malakhova N. G. Furmanova A. I. Vilensky M. S. Grigorieva V. I. Simonov E. B. Rudneva A. É. Voloshin 《Crystallography Reports》2009,54(2):211-218
The precision X-ray structural investigation of KH2PO4 (KDP) crystal samples from different growth sectors of a single crystal containing chromium impurities is performed. It is demonstrated that the structure of the sample from the prismatic growth sector is more perfect than the structure of the sample from the pyramidal growth sector. The impurity trapping can lead to the formation of at least four different types of structural defects on the face of the pyramid, whereas only two of them can be formed on the face of the prism. A comparison with the relevant data for the “pure” KDP crystal shows that the number of defects and their character are approximately identical for all samples. The analysis of the IR spectra indicates that nitrate ions are contained in the samples from both growth sectors. Moreover, structurally bound water molecules and OH groups are revealed in the sample from the prismatic sector. 相似文献
19.
Atomic force microscopy is used to investigate the surface morphology of the prismatic (100) face of ZCTC crystal grown at 30°C at a supersaturation of 0.16. This surface is distinctly formed by periodic “macrosteps” that advance along different directions and join with each other leading to the interlaced growth layers with an inclination of about 137°. These two “macrostep” trains well correspond to the pyramidal faces of (0 ) and (01 ) in orientation, therefore they probably propagate from the edges of these faces. The “macrosteps” are practically formed by highly dense steps at the front with regular elementary steps in between. The alternation of “macrosteps” and elementary steps vividly reflects Chernov's “kinematic waves of steps” theory (Chernov , (1984)) on a nanometer scale. Wide indentations and long clefts are generated at the “macrosteps”. The former is generated by twodimensional nucleation growth at a relatively faster growth rate than that of the underlying layer. The latter is probably caused by step trains generated by individual growth sources that have not merged. 相似文献