Physical Properties of C-Si Alloys in C2/m Structure

• 来源期刊: 理论物理通讯（英文版）
• 年，卷（期）: 2017,（8）
• 页码范围: 259-268
• 页数: 10页
• 语种: 英文
• DOI: 10.1088/0253-6102/68/2/259

摘要

Using the first principles calculations based on density functional theory,the crystal structure,elastic anisotropy,and electronic properties of carbon,silicon and their alloys (C12Si4,CsSis,and C4Si12) in a monoclinic structure (C2/m) are investigated.The calculated results such as lattice parameters,elastic constants,bulk modulus,and shear modulus of C16 and Si16 in C2/m structure are in good accord with previous work.The elastic constants show that C16,Si16,and their elloys in C2/m structure are mechanically stable.The calculated results of universal anisotropy index,compression and shear anisotropy percent factors indicate that C-Si alloys present elastic anisotropy,and C8Si8 shows a greater anisotropy.The Poisson's ratio and the B/G value show that C8Si8 is ductile material and other four C-Si alloys are brittle materials.In addition,Debye temperature and average sound velocity are predicted utilizing elastic modulus and density of C-Si alloys.The band structure and the partial density of states imply that C16 and Si16 are indirect band gap semiconductors,while C12Si4,C8Si8,and C4Si12 are semi-metallic alloys.