Ta_2N_3电子结构与光学性质的第一性原理研究  

First-principles Calculations for the Electronic Structure and Optical Properties of Ta_2N_3

作　　者：马松山[1] 徐慧[1] 夏庆林[1] 

机构地区：[1]中南大学物理科学与技术学院,长沙410083

出　　处：《材料导报》2010年第14期74-77,共4页Materials Reports

基　　金：高等学校博士点专项科研基金(20070533075);湖南省科技计划项目(2009FJ3004)

摘　　要：基于密度泛函第一性原理的GGA方法计算研究了Ta2N3的能带结构、态密度、分态密度和光学性质。计算结果表明,Ta2N3具有明显的金属能带结构特征,且在费米能级附近,Ta的5d态与N的2p态杂化,Ta-N以共价键相互作用。Ta2N3的静态介电常数为77.428,静态的折射率n0为8.88,而介电函数的虚部随能量的增加而减小。Ta2N3多晶体的反射系数在0～1.65eV区域随能量的增加而逐渐减小,在1.65eV附近达极小值,此后随能量的增加而增大,但在15eV时发生陡降。Ta2N3多晶体的吸收系数数量级达105cm-1,且在高能区对光子的吸收较少,其电子能量损失谱(EELS)的共振峰在15eV处,与此能量时反射系数的陡降相对应。The band structure, density of states and optical properties of Ta2N3 are investigated, by the generalized gradient approximation（GGA） based on density functional theory of first-principles calculations. The band structure of Ta2N3 indicates it is a kind of metallic material, hybridization Between N 2p and Ta 5d state, an evidence of covalent Bonding between N and Ta atoms. The static dielectric constant of Ta2 Na is 77. 428, and the static refractive index is 8. 88. For the imaginary part of dielectric constant, it is decrease with the increase of the energy. In 0-1.65eV,the reflection index decreases with the increase of the energy, while in 1.65-15eV the reflection index increases with the increase of the energy, and there is an abrupt reduction at 15eV, Which corresponding to the peak of EELS. The absorption coefficient is as large as 105 cm^-1, and the absorption is mainly localized in the low energy region

关 键 词：Ta2N3 电子结构 光学性质 第一性原理 

分 类 号：O561.2[理学—原子与分子物理]