Ab initio study of structural, dielectric, and dynamical properties of zinc-blende ZnX (X = O, S, Se, Te)

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• 作者：You Yu ; Jingjing Zhou ; Huilei Han ; Chuanyu Zhang ; Tuo Cai ; Chengqun Song ; Tao Gao
• 关键词：Linear-response approach ; DFPT ; Dielectric properties
• 刊名：Journal of Alloys and Compounds
• 出版年：2009
• 出版时间：5 March 2009
• 年：2009
• 卷：471
• 期：1-2
• 页码：492-497
• 全文大小：393 K

文摘

We have performed ab initio calculations of the structural, dielectric, and lattice-dynamical properties of the zinc-blende ZnX (X = O, S, Se, Te) using a plane-wave pseudopotential method within the density-functional theory. A linear-response approach to the density-functional theory as implemented in the code ABINIT is used to calculate the Born effective charges, electronic dielectric tensors, phonon frequencies and LO–TO splitting. Compared to the direct approach (or frozen-phonon approach), the linear-response approach has important advantages in that time-consuming supercell calculations are avoided and phonons of arbitrary wave vector can be treated with a cost that is independent of wave vector. The calculated bulk lattice constant values of 4.616 Å, 5.392 Å, 5.674 Å, and 6.226 Å for ZnO, ZnS, ZnSe and ZnTe, respectively, were used for phonon calculations. The LO–TO splitting frequencies (in cm⁻¹) at the zone-center (Γ point) are ZnO: LO = 517, TO = 367; ZnS: LO = 333, TO = 267; ZnSe: LO = 245, 205; ZnTe: LO = 188, TO = 161. The computed values are in reasonable agreement with experimental data and other calculations.