Structural, phonon, mechanical, optical, and thermodynamic properties of stable β-La_2S_3 from first-principles calculations

作     者：张显 桂文华 吴茜 曾庆丰 

作者机构：School of Advanced Materials and NanotechnologyXidian University International Center for Materials DiscoverySchool of Materials Science and EngineeringNorthwestern Polytechnical University 

出 版 物：《Journal of Rare Earths》 (稀土学报（英文版）)

年 卷 期：2017年第35卷第3期

页      面：271-279页

核心收录：

学科分类：0709[理学-地质学] 0819[工学-矿业工程] 07[理学] 0708[理学-地球物理学] 0703[理学-化学] 070301[理学-无机化学] 

基　　金：supported by National Natural Science Foundation of China(51372203 51332004 51571166 11304238) 

主　　题：β-La2S3 first-principles optical properties elastic constant thermodynamic properties rare earths 

摘      要：The band structures,density of states,phonon,optical properties,and thermodynamic properties of β-La_2S_3 were calculated from first-principles using the plane-wave pseudopotential method.First,the structures were fully relaxed through the first-principles method.Then,the zone-center phonon-mode frequencies were evaluated within the framework of density functional perturbation theory.Properties related to the structure,phonons,optics,elastic constants,and thermodynamics of β-La_2S_3 were reported.The dielectric function,refractive index,absorption coefficient,extinction coefficient,infrared（IR） reflectance,energy,heat capacity,and Debye temperature spectra were also given β-La_2S_3 was a direct-gap semiconductor,and calculation indicated that its energy gap was 0.191 eV.From the phonon spectra,it could be concluded that the lattice dynamics were stable.A strong IR reflection occurred in a range of 0-1000 nm,arising from several strong IR-active modes,resulting in poor transmission properties.Relatively good transmission properties were observed in the range above 2000 nm,with low reflectivity and dissipation due to the absence of IR-active or weak modes.