CAJ | 학술논문

采用密度泛函理论的定域密度和一般梯度近似,研究了Si3P4 5个相的结构、电子和弹性性质.考虑的Si3P4结构包括分别具有空间群P63/m,Fd-3m,P-42m,IM-3M,P-43m的β,γ,膺立方、立方和缺损立方相.总的能量计算表明,具有缺损闪锌矿结构的膺立方和缺损立方相相对于其它相能量最低,因而是最稳定的2个相.弹性常数计算表明,两个相对稳定的相有大的应变模量,因而结构上较硬.能带结构和分波态密度计算表明,在两种近似下,膺立方和缺损立方是半导体,而β,γ和立方相是金属.
채용밀도범함이론적정역밀도화일반제도근사,연구료Si3P4 5개상적결구、전자화탄성성질.고필적Si3P4결구포괄분별구유공간군P63/m,Fd-3m,P-42m,IM-3M,P-43m적β,γ,응립방、립방화결손립방상.총적능량계산표명,구유결손섬자광결구적응립방화결손립방상상대우기타상능량최저,인이시최은정적2개상.탄성상수계산표명,량개상대은정적상유대적응변모량,인이결구상교경.능대결구화분파태밀도계산표명,재량충근사하,응립방화결손립방시반도체,이β,γ화립방상시금속.
Using local-density approximation (LDA) and generalized-gradient approximation (GGA) based on density-functional theory (DFT), we investigated the structural, electronic and elastic properties of the five crystal phases of Si3 P4, i.e. β-,γ-, pseudocubic-, cubic-, and cubic-defect-Si3P4 phases, with their space groups P63/m, Fd3m, P-42m, IM-3M, and P-43m, respectively. Total-energy calculations indicated that the pseudocubic and the defect cubic phases with their defect zinc-blende structures are energetically favorable relative to other Si3P4 phases.The calculation of elastic constants showed that the two energetically favored phases have large shear moduli as compared to those obtained in the other phases. The band-structure and partial density-of-states reveal that pseudocubic and defect cubic phases are semi-conducting, while β,γ and cubic phases are metallic.