{"title":"用第一性原理计算研究Cmc21-Si2P2X的结构和物理性质","authors":"R. Yang, X. Gao, F. Wu, Q. Wei, M. Xue","doi":"10.5488/CMP.24.43602","DOIUrl":null,"url":null,"abstract":"The new structures, Cmc21-Si2P2X (X=S, Se, Te, and Po), are predicted, and their mechanical, electronic and optical properties are investigated with the density functional theory, by first principles calculations. The elastic constants of the four compounds are calculated by the stress-strain method. The calculations of the elastic stability criteria and phonon dispersion spectra imply that they are mechanically and dynamically stable at zero pressure. The mechanical parameters, such as shear moduli G, bulk moduli B, Young's moduli E and Poisson's ratios v are evaluated by the Voigt-Reuss-Hill approach. The Cmc21-Si2P2X has the largest hardness due to the largest Young's modulus in the four compounds, and it is a covalent crystal. The anisotropies of their mechanical properties are also analyzed. The band structures and densities of states, which are calculated by using HSE06, show that Cmc21-Si2P2X compounds are indirect bandgap semiconductors, and the values of the band gaps decrease with increasing atomic number from S, Se, Te, to Po. In addition, the longitudinal sound velocity and transverse sound velocity for Cmc21-Si2P2X have been investigated. The dielectric constant, electron energy loss, refractive index, reflectivity, absorption and conductivity are analyzed to gain the optical properties of Si2P2X.","PeriodicalId":10528,"journal":{"name":"Condensed Matter Physics","volume":"4 1","pages":""},"PeriodicalIF":0.9000,"publicationDate":"2021-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Investigations on Cmc21-Si2P2X structures and physical properties by first-principles calculations\",\"authors\":\"R. Yang, X. Gao, F. Wu, Q. Wei, M. Xue\",\"doi\":\"10.5488/CMP.24.43602\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"The new structures, Cmc21-Si2P2X (X=S, Se, Te, and Po), are predicted, and their mechanical, electronic and optical properties are investigated with the density functional theory, by first principles calculations. The elastic constants of the four compounds are calculated by the stress-strain method. The calculations of the elastic stability criteria and phonon dispersion spectra imply that they are mechanically and dynamically stable at zero pressure. The mechanical parameters, such as shear moduli G, bulk moduli B, Young's moduli E and Poisson's ratios v are evaluated by the Voigt-Reuss-Hill approach. The Cmc21-Si2P2X has the largest hardness due to the largest Young's modulus in the four compounds, and it is a covalent crystal. The anisotropies of their mechanical properties are also analyzed. The band structures and densities of states, which are calculated by using HSE06, show that Cmc21-Si2P2X compounds are indirect bandgap semiconductors, and the values of the band gaps decrease with increasing atomic number from S, Se, Te, to Po. In addition, the longitudinal sound velocity and transverse sound velocity for Cmc21-Si2P2X have been investigated. The dielectric constant, electron energy loss, refractive index, reflectivity, absorption and conductivity are analyzed to gain the optical properties of Si2P2X.\",\"PeriodicalId\":10528,\"journal\":{\"name\":\"Condensed Matter Physics\",\"volume\":\"4 1\",\"pages\":\"\"},\"PeriodicalIF\":0.9000,\"publicationDate\":\"2021-12-18\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Condensed Matter Physics\",\"FirstCategoryId\":\"101\",\"ListUrlMain\":\"https://doi.org/10.5488/CMP.24.43602\",\"RegionNum\":4,\"RegionCategory\":\"物理与天体物理\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q4\",\"JCRName\":\"PHYSICS, CONDENSED MATTER\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Condensed Matter Physics","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.5488/CMP.24.43602","RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"PHYSICS, CONDENSED MATTER","Score":null,"Total":0}
引用次数: 0
摘要
预测了新结构Cmc21-Si2P2X (X=S, Se, Te和Po),并通过第一性原理计算用密度泛函理论研究了它们的力学、电子和光学性质。采用应力-应变法计算了四种化合物的弹性常数。弹性稳定性判据和声子色散谱的计算表明它们在零压力下是机械和动态稳定的。采用Voigt-Reuss-Hill方法计算了剪切模量G、体模量B、杨氏模量E和泊松比v等力学参数。Cmc21-Si2P2X由于杨氏模量最大而具有最大的硬度,并且是共价晶体。分析了其力学性能的各向异性。用HSE06计算的能带结构和态密度表明,Cmc21-Si2P2X化合物是间接带隙半导体,从S、Se、Te到Po,带隙值随着原子序数的增加而减小。此外,还研究了Cmc21-Si2P2X的纵向声速和横向声速。分析了Si2P2X的介电常数、电子能量损失、折射率、反射率、吸收和电导率等参数,得到了Si2P2X的光学特性。
Investigations on Cmc21-Si2P2X structures and physical properties by first-principles calculations
The new structures, Cmc21-Si2P2X (X=S, Se, Te, and Po), are predicted, and their mechanical, electronic and optical properties are investigated with the density functional theory, by first principles calculations. The elastic constants of the four compounds are calculated by the stress-strain method. The calculations of the elastic stability criteria and phonon dispersion spectra imply that they are mechanically and dynamically stable at zero pressure. The mechanical parameters, such as shear moduli G, bulk moduli B, Young's moduli E and Poisson's ratios v are evaluated by the Voigt-Reuss-Hill approach. The Cmc21-Si2P2X has the largest hardness due to the largest Young's modulus in the four compounds, and it is a covalent crystal. The anisotropies of their mechanical properties are also analyzed. The band structures and densities of states, which are calculated by using HSE06, show that Cmc21-Si2P2X compounds are indirect bandgap semiconductors, and the values of the band gaps decrease with increasing atomic number from S, Se, Te, to Po. In addition, the longitudinal sound velocity and transverse sound velocity for Cmc21-Si2P2X have been investigated. The dielectric constant, electron energy loss, refractive index, reflectivity, absorption and conductivity are analyzed to gain the optical properties of Si2P2X.
期刊介绍:
Condensed Matter Physics contains original and review articles in the field of statistical mechanics and thermodynamics of equilibrium and nonequilibrium processes, relativistic mechanics of interacting particle systems.The main attention is paid to physics of solid, liquid and amorphous systems, phase equilibria and phase transitions, thermal, structural, electric, magnetic and optical properties of condensed matter. Condensed Matter Physics is published quarterly.