WO3晶体生长与形貌的数值模拟

Numerical Simulation of Crystal Growth and Morphology of WO3

利用分子模拟软件Material Studio7.0创建WO3晶体中(011)、(101)、(110)和(110)晶面的真空slab(crystal structure model)模型,并通过CASTEP程序计算其总能量、表面能与电子结构。利用Morphology程序,采用BFDH法则对WO3晶体和各晶面slab模型进行晶习预测。计算结果表明,在晶体生长过程中,若以(110)晶面为主要显露面,则WO3晶体能量状态稳定性较差;以(011)晶面为主要显露面,则WO3晶体能量状态稳定。费米能级最小的(110)晶面前线价电子不太活跃,存在电子结构动力学稳定性;费米能级最高的(110)晶面前线价电子活跃,存在与晶体生长基元键合的"活性点"。(011)面slab模型的最小能区宽度最小而态密度峰值最大,表明其内层电子较为稳定。BFDH法则预测结果表明,WO3晶体与各面slab模型的生长习性相同,都趋向于生长为立方体状晶体。另外,WO3晶体中最重要的生长面为(001)和(001)面。

The vacuum slab models(crystal structure models)of crystal planes(011),(101),(110)and(110)in WO3 crystal were calculated by the molecular simulation software Material Studio7.0,and the total energy,surface energy and electronic structure were calculated by CASTEP program.Using the Morphology program,the growth habits of WO3 crystal and the slab model of each crystal plane were predicted by BFDH rule.The results of calculation show that the energy stability of WO3 crystal is poor in the process of crystal growth when plane(110)is the main unfolded,while the energy state of the WO3 crystal is stable when plane(011)is the main unfolded.The front valence electron of plane(110)with the smallest Fermi energy is not active,and there is relative stability of electronic structure dynamics.The front valence electron of plane(110)with the highest Fermi energy is active,which means there is an activity point on this plane that can be bonded to crystal growth matrix.The slab model of plane(011)has the smallest minimum energy region width and the largest state density peak value,which indicates the inner electron is relatively stable.The predicted results of the BFDH rule show that the growth habit of the WO3 crystal is consist with the slab model,which tends to grow to cubic crystal.In addition,the most important growth planes in WO3 crystal are(001)and(001).