Surface energies and appearances of commonly exposed surfaces of scheelite crystal  

白钨矿晶体常见暴露面的表面能及表面形貌(英文)

作　　者：高志勇[1] 孙伟[1] 胡岳华[1] 刘晓文[1] 

机构地区：[1]中南大学资源加工与生物工程学院,长沙410083

出　　处：《Transactions of Nonferrous Metals Society of China》2013年第7期2147-2152,共6页中国有色金属学报（英文版）

基　　金：Project(50831006)supported by the National Natural Science Foundation of China;Project(CX2011B122)supported by Hunan Provincial Innovation Foundation for Postgraduate,China;Project(2012BAB10B05)supported by the National Key Technologies R&D Program of China

摘　　要：Surface energies of five different surfaces of scheelite crystal were calculated using density functional theory （DFT）. Based on the calculation results, the predominantly exposed surfaces in the morphologies of scheelite crystals were predicted. {112} and {001} cleavage surfaces and {112} crystal surface are the commonly exposed surfaces, which are consistent with both previous literatures and the present experimental observations based on the XRD. Cleavage generates more easily along {112} surfaces than along {001} surfaces due to their different interlayer spacings. The surface roughness and appearance of different predominantly exposed surfaces were then investigated using AFM. The roughness of smooth {112} cleavage surface is the lowest among these three surfaces. On {001} cleavage surface, terraces are flat and separated by steps of about 10 nm in height. Subsequently, contact angle measurements were adopted to evaluate the wettability and surface energies of these surfaces. The surface energies evaluated directly correspond to the trend calculated with DFT.采用密度泛函理论DFT计算白钨矿晶体5个晶面的表面能,预测白钨矿晶体常见的暴露面。预测分析表明,{112}和{001}解理面及{112}晶面是白钨矿晶体的3个主要暴露面,与文献报道的及XRD单晶衍射实验结果一致。较{001}面方向,沿{112}面层间更容易产生解理,可能与这两个晶面方向的层间距差异有关。采用AFM研究3个常见暴露面的表面形貌。研究表明,{112}解理面最光滑,粗糙度最小;在{001}解理面上高度约10nm的台阶依次排列。采用接触角测量的方法研究3个暴露面的润湿性,并计算其表面能。计算所得的表面能数据与DFT计算值大小顺序一致。

关 键 词：SCHEELITE surface energy CLEAVAGE contact angle WETTABILITY 

分 类 号：P573[天文地球—矿物学]