高压下CaF2结构相变和光学性质的第一性原理计算

杨晓翠; 赵玉伟; 高忠明; 刘鑫; 张立新; 王晓明; 郝爱民

doi:10.11858/gywlxb.2010.03.011

高压下CaF2结构相变和光学性质的第一性原理计算

doi: 10.11858/gywlxb.2010.03.011

1.
白城师范学院物理系，吉林白城 137000；
2.
河北科技师范学院理化学院，河北秦皇岛 066004；
3.
燕山大学亚稳材料制备技术与科学国家重点实验室，河北秦皇岛 066004

详细信息

通讯作者:
郝爱民

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出版历程
- 收稿日期: 2009-05-27
- 修回日期: 2009-09-28
- 发布日期: 2010-06-15

First-Principles Study of Structural Stabilities, Electronic and Optical Properties of CaF2 under High Pressure

1.
Department of Physics, Baicheng Normal College, Baicheng 137000, China;
2.
College of Physics and Chemistry, Hebei Normal University of Science and Technology, Qinhuangdao 066004, China;
3.
State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, China

More Information

Corresponding author: HAO Ai-Min

摘要

摘要: 利用基于密度泛函理论的第一性原理方法，计算了在压力作用下CaF2的结构相变和光学性质。结果证实了CaF2的压致结构转变的顺序是从氟石结构（空间群Fm3m）转变到PbCl2型结构（空间群Pnma），然后继续转变为Ni2In型结构（空间群P63/mmc）。在Fm3m和Pnma两种结构中，电子带隙随着压力的增加而增加，而在P63/mmc结构中，带隙随着压力的增加开始下降。实验结果显示，直到210 GPa，CaF2没有发生由绝缘体到金属的转变。据此推测，CaF2的金属化压力高于300 GPa。还讨论了压力对CaF2光学性质的影响。
- 第一性原理计算 /
- 相变 /
- 高压 /
- 光学性质
Abstract: An investigation on the structural stabilities and electronic properties of CaF2 under high pressure was conducted using first-principle calculation based on density functional theory (DFT) with the plane wave basis set as implemented in the CASTEP code. Our results demonstrate that the sequence of the pressure-induced phase transition of CaF2 is the fluorite structure (Fm3m) to the PbCl2-type structure (Pnma), and to the Ni2In-type phase (P63/mmc). The energy gap increases with pressure in the Fm3m and Pnma phases, then begins to decrease in the P63/mmc phase. The band gap overlap metallization does not occur up to 210 GPa. It is predicted that the metallization pressure of CaF2 should be over 300 GPa. The pressure effect on the optical properties is discussed.
- first-principles calculations /
- phase transition /
- high pressure /
- optical property

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参考文献(17)

Rubloff G W. Far-Ultraviolet Reflectance Spectra and the Electronic Structure of Ionic Crystals [J]. Phys Rev B, 1972, 5: 662-684.

Oberschmidt J, Lazarus D. Ionic Conductivity, Activation Volumes, and High-Pressure Phase Transitions in PbF2 and SrCl2 [J]. Phys Rev B, 1980, 21: 2952-2961.

Reed A D, Lazarus D. Ionic Conductivity in Superionic SrF2 [J]. Phys Rev, 1983, 27: 6504-6506.

Gan F, Xu Y N, Huang M Z, et al. Optical Properties of a CaF2 Crystal [J]. Phys Rev B, 1992, 45: 8248-8255.

Kourouklis G A, Anastassakis E. Pressure-Induced Phase Transition in SrF2: A Raman Study [J]. Phys Rev B, 1986, 34: 1233-1237.

Leger J M, Haines J, Atouf A, et al. High-Pressure X-Ray- and Neutron-Diffraction Studies of BaF2: An Example of a Coordination Number of 11 in AX2 Compounds [J]. Phys Rev B, 1995, 52: 13247-13256.

Ayala A P. Atomistic Simulations of the Pressure-Induced Phase Transitions in BaF2 Crystals [J]. J Phys: Condens Matter, 2001, 13: 11741-11749.

Khenata R, Daoudi B, Sahnoun M, et al. Structural, Electronic and Optical Properties of Fluorite-Type Compounds [J]. Eur Phys J B, 2005, 47: 63-70.

Kanchana V, Vaitheeswaran G, Rajagopalan M. Structural Phase Stability of CaF2 and SrF2 under Pressure [J]. Physica B, 2003, 328: 283-290.

Wu X, Qin S, Wu Z Y. First-Principles Study of Structural Stabilities, and Electronic and Optical Properties of CaF2 under High Pressure [J]. Phys Rev B, 2006, 73: 134103-1-8.

Segall M D, Lindan P L D, Probert M J, et al. First-Principles Simulation: Ideas, Illustrations and the CASTEP Code [J]. J Phys: Condens Matter, 2002, 14: 2717-2744.

Perdew J P, Burke K, Ernzerhof M. Generalized Gradient Approximation Made Simple [J]. Phys Rev Lett, 1996, 77: 3865-3868.

Gerward L, Olsen J S, Steenstrup S, et al. X-Ray Diffraction Investigations of CaF2 at High Pressure [J]. J Appl Crystallogr, 1992, 25: 578-581.

Kalpana G, Palanivel B, Rajagopalan M. Electronic Structure and Structural Phase Stability in BaS, BaSe and BaTe [J]. Phys Rev B, 1994, 50: 12318-12325.

Scrocco M. Satellites in X-Ray Photoelectron Spectroscopy of Insulators. Ⅰ. Multielectron Excitations in CaF2, SrF2 and BaF2 [J]. Phys Rev B, 1985, 32: 1301-1305.

Speziale S, Duffy T S. Single-Crystal Elastic Constants of Fluorite (CaF2) to 9. 3 GPa [J]. Phys Chem Miner, 2002, 29: 465-472.

Hamann D R, Schluter M, Chiang C. Norm-Conserving Pseudopotentials [J]. Phys Rev Lett, 1979, 43: 1494-1497.

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