高等学校化学学报 ›› 2015, Vol. 36 ›› Issue (12): 2497.doi: 10.7503/cjcu20150352

• 物理化学 • 上一篇    下一篇

NiCl2晶体生长的数值模拟

肖志夏, 朱艳丽(), 赵勇, 邢家超, 焦清介   

  1. 北京理工大学爆炸科学与技术国家重点实验室, 北京100081
  • 收稿日期:2015-04-30 出版日期:2015-12-10 发布日期:2015-11-17
  • 作者简介:联系人简介: 朱艳丽, 女, 博士, 副教授, 主要从事电极材料研究. E-mail:zhuyanli1999@bit.edu.cn
  • 基金资助:
    国家自然科学基金(批准号: 51304024, 11172042)和国家科技支撑计划(批准号: 2013BAE04B02)资助

Simulation on the Growth of NiCl2 Crystal

XIAO Zhixia, ZHU Yanli*(), ZHAO Yong, XING Jiachao, JIAO Qingjie   

  1. State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, China
  • Received:2015-04-30 Online:2015-12-10 Published:2015-11-17
  • Contact: ZHU Yanli E-mail:zhuyanli1999@bit.edu.cn
  • Supported by:
    † Supported by the National Natural Science Foundation of China(Nos.51304024, 11172042) and the National Key Technology Support Program(No.2013BAE04B02)

摘要:

利用剑桥总能量连续软件包(CASTEP)程序, 采用密度泛函理论(DFT)对NiCl2晶体(003), (101), (104), (018)和(113)面真空slab模型进行了总能量、 表面能以及能带结构和态密度的计算, 采用布拉维法则和唐纳-哈克定律(BFDH)形貌预测方法对氯化镍晶体形貌及其各晶面生长习性进行了计算. 收敛性测试结果表明真空层厚度为0.6 nm及模型厚度为3层原子对表面能计算影响较小. DFT计算结果显示, 当氯化镍晶体以(003)面为主要显露面时, 能量状态较为稳定, 而以(101), (104), (018)和(113)面显露较多时, 则能量稳定性较差. (003)面的前线价电子较为活跃, 其晶面可能存在与溶液中离子、 分子或是晶体生长基元发生键合的“活性点”, 能隙较大说明该面内层电子较为稳定. 能带结构和态密度图分析显示(003)面费米能级附近能量较高的能带数量少于其它晶面, 再次证明其为主要显露面时体系热力学性质较为稳定. BFDH对氯化镍晶体形貌的计算成功预测了显露面族(003)和(101), 并且(003)面是最重要晶面. 计算结果表明, 氯化镍晶胞和各表面真空slab模型的生长习性存在差异, 氯化镍晶胞、 (003)、 (101)和(113)面slab模型均趋向于生长为六棱柱或六角板状晶体, (104)和(018)面slab模型则趋向于生长为棒状晶体.

关键词: 氯化镍, 表面能, 密度泛函理论, 晶体形貌

Abstract:

Based on the density function theory(DFT) calculation of crystal faces (003), (101), (104), (018) and (113) of NiCl2 via CASTEP program, total energy, surface energy, band structures and density of states(DOS) were investigated. The crystal morphology of NiCl2 and the growth habit of the surface of NiCl2 were calculated by Bravais-Friedel Donnay-Harker(BFDH) rules. The results show that vacuum width of 0.6 nm and atom layer of 3 are reasonable to the surface energy calcution. The energy state of NiCl2 is far more stable when face (003) is mainly unfold faces, while the energy state would be instable when faces (101), (104), (018) and (113) are the mainly unfolded. The electric structure results show that the front valence electron of face (003) is active correspondingly. That is there may be some activity points on this face. The larger energy band gap of it shows that the inner electrons are more stable. The band structures and DOS analysis show that the number of high energy band of (003) slab near the Fermi energy is less than that of other slabs, which proves the system is more stable no thermodynamics when (003) is mainly unfold.BFDH calculation on NiCl2 predicts the unfold faces (003) and (101) successfully and indicates (003) is the most important face. Other results show that the growth habits of NiCl2 cell and its surface slabs are different, NiCl2 cell, (003), (101) and (113) slabs are inclined to form crystal with hexagonal plate and bulk shapes, (104) and (018) slabs are inclined to form crystal with rod shape.

Key words: Nickel chloride, Surface energy, Density functional theory, Crystal morphology

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