二维平移法小尺寸KDP单晶生长溶液流动与传质模拟  

Numerical Simulation of Flow and Mass Transfer for Small-size KDP Crystals Grown by 2D Translation Method

作　　者：尹华伟 胡传波 姚鑫 陈琪雅 胡雷 卢增辉 YIN Huawei;HU Chuanbo;YAO Xin;CHEN Qiya;HU Lei;LU Zenghui(Key Laboratory of Water Environment Evolution and Pollution Control in Three Gorges Reservoir,School of Environmental and Chemical Engineering,Chongqing Three Gorges University,Chongqing 404000,China;HKBU Faculty of Science,Hongkong 999077,China;Wanzhou Ecological Environmental Monitoring Station,Chongqing 404000,China)

机构地区：[1]三峡库区水环境演变与污染防治重庆市重点实验室,重庆三峡学院环境与化学工程学院,重庆404000 [2]香港浸会大学理学院,中国香港999077 [3]重庆市万州区生态环境监测站,重庆404000

出　　处：《材料导报》2021年第12期12032-12038,共7页Materials Reports

基　　金：重庆市教育委员会科学技术研究计划项目(KJQN201901223,KJQN201901228);重庆市自然科学基金项目(cstc2020jcyj-msxmX0826)。

摘　　要：二维平移法是一种新型的晶体生长方法。在该方法中,晶体不再作正反转运动,而是沿着特定轨迹作周期性的平移运动。本工作对二维平移法小尺寸磷酸二氢钾(KDP)单晶生长过程进行了数值模拟研究,获得了不同平移速度、不同平移距离以及不同迎流角度下晶体附近溶液流动与晶面过饱和度分布。结果表明:增加平移速度,晶面过饱和度随之增加,但流场结构并无明显变化;增大平移距离,晶面的过饱和度反而降低,标准差则有逐渐增大的趋势,这不利于提高过饱和度均匀性;不同迎流角度下,柱面的过饱和度分布差异较大,对流的不对称性也更加明显,当迎流角度为45°时,对晶体生长更有利。此外,台阶推移结果表明,不均匀的过饱和度会造成台阶弯曲和聚并,二维平移法更利于台阶稳定推移,有望提高形貌稳定性和晶体质量。A novel technique of crystal growth named 2D translation method is proposed.In this method,the crystal is periodically translated according to the scheduled path instead of reversal rotation.Numerical simulations of the growth process of the small-size KDP single crystal via 2D translation method were carried out.The fluid flow and surface supersaturation distribution are obtained as functions of the translational velocity,distance,impacted angle of crystals.Results indicate that surface supersaturation increases with an increase in translational velocity.However,the change in the structure of the flow field is not pronounced.With increased translation distance,the mean value of surface supersaturation gradually decreases,whereas standard deviation increases,which is detrimental to the homogeneity of surface supersaturation.Impacted angle considerably affects the distribution of the prismatic surface supersaturation and the symmetry of the flow field.Results show that it is more favorable for crystal growth when the impacted angle is 45°.The simulation for step propagation shows that the non-uniform distribution of surface supersaturation can give rise to step bending and bunching.2D translation method is more conducive to the steady step migration,which is expected to improve the morphology stability and crystal quality.

关 键 词：二维平移法 数值模拟 KDP单晶 过饱和度分布 形貌稳定性 

分 类 号：O78[理学—晶体学]