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高压下SiO2的第一性原理计算

DOI: 10.11858/gywlxb.2010.04.004, PP. 260-266

Keywords: 第一性原理,相变,密度泛函理论,电子态密度

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Abstract:

基于密度泛函理论(DFT)的第一性原理,采用Hartree-Fork(HF)方法,分别计算了SiO2的α-石英结构、金红石结构以及氯化钙结构的总能量随体积的变化关系。利用Murnaghan状态方程,通过能量和体积拟合,得到了3种结构的体变模量及其对压强的一阶导数。计算结果表明,随着压强的增加,SiO2会从α-石英结构转变为金红石结构,与实验结果和其它理论结果一致;金红石结构与氯化钙结构之间不存在相变,可以共存。此外,对具有α-石英结构的SiO2的晶格常数、电子态密度和带隙随压强的变化关系进行了计算和分析,结果表明:加压作用下,能带向高能方向移动,Si─O键缩短,电子数转移增加,带隙展宽,电荷发生重新分布。

References

[1]  Kingma K J, Cohen R E, Hemley R J, et al. Transformation of Stishovite to a Denser Phase at Lower-Mantle Pressures [J]. Nature, 1995, 374(6519): 243-245.
[2]  Tsuchida Y, Yagi T. New Pressure-Induced Transformations of Silica at Room Temperature [J]. Nature, 1990, 347: 267-269.
[3]  Belonoshko A B, Dubrovinsky L S, Dubrovinsky N A. A New High-Pressure Silica Phase Obtained by Molecular Dynamics [J]. Am Mineral, 1996, 81: 785-788.
[4]  Dubrovinsky L S, Saxena S K, Lazor P, et al. Experimental and Theoretical Identification of a New High-Pressure Phase of Silica [J]. Nature, 1997, 388(6640): 362-365.
[5]  Liu L G, Bassett W A, Sharry J. New High-Pressure Modifications of GeO2 and SiO2 [J]. J Geophys Res, 1978, 83: 2301-2305.
[6]  German V N, Podurets M A, Trunin R F. Synthesis of a High-Density Phase of Silicon Dioxide in Shock Waves [J]. Sov Phys JETP, 1973, 37: 107-108.
[7]  Levien L, Prewitt C T, Weidner D J. Structure and Elastic Properties of Quartz at Pressure [J]. Am Mineral, 1980, 65(9-10): 920-930.
[8]  Tsuchida Y, Yagi T. A New, Post-Stishovite High-Pressure Polymorph of Silica [J]. Nature, 1989, 340: 217-220.
[9]  Teter D M, Hemley R J, Kresse G, et al. High Pressure Polymorphism in Silica [J]. Phys Rev Lett, 1998, 80(10): 2145-2148.
[10]  Nada R, Nicholas J B, McCarthy M I, et al. Basis Sets for ab Initio Periodic-Fock Studies of Zeolite/Adsorbate Interactions: He, Ne, and Ar in Silica Sodalite [J]. Int J Quantum Chem, 1996, 60(4): 809-820.
[11]  Corno M, Busco C, Civalleri B, et al. Periodic ab Initio Study of Structural and Vibrational Features of Hexagonal Hydroxyapatite Ca10(PO4)6(OH)2 [J]. Phys Chem Chem Phys, 2006, 8(21): 2464-2472.
[12]  Jaffe J E, Pandey R, Seel M J. Ab Initio High-Pressure Structural and Electronic Properties of ZnS [J]. Phys Rev B, 1993, 47(11): 6299-6303.
[13]  Orlando R, Dovesi R, Roetti C, et al. Ab Initio Hartree-Fock Calculations for Periodic Compounds: Application to Semiconductors [J]. J Phys: Condens Matter, 1990, 2(38): 7769-7789.
[14]  Murnaghan F D. The Compressibility of Media under Extreme Pressures [J]. Proc Natl Acad Sci U S A, 1944, 30(9): 244-247.
[15]  Jaffe J E, Hess A C. Hartree-Fock Study of Phase Changes in ZnO at High Pressure [J]. Phys Rev B, 1993, 48(11): 7903-7909.
[16]  Keskar N R, Chelikowsky J R. Structural Properties of Nine Silica Polymorphs [J]. Phys Rev B, 1992, 46(1): 1-13.
[17]  Stishov S M, Popova S V. A New Dense Modification of Silica [J]. Geokhimiya, 1961, 10: 837-839.
[18]  Lityagina L M, Dyuzheva T I, Nikolaev N A, et al. Hydrothermal Crystal Growth of Stishovite (SiO2) [J]. J Cryst Growth, 2001, 222(3): 627-629.
[19]  Karki B B, Warren M C, Stixrude L, et al. Ab Initio Studies of High-Pressure Structural Transformations in Silica [J]. Phys Rev B, 1997, 55(6): 3465-3471.
[20]  Maj S. Energy Gap and Density in SiO2 Polymorphs [J]. Phys Chem Miner, 1988, 15(3): 271-273.
[21]  Nitsan U, Shankland T J. Optical Energy Gap in Silicates [J]. EOS, 1976, 57(3): 160.

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