摘要
采用基于密度泛函理论的第一性原理平面波赝势法研究Sc掺杂对β-Si_(3)N_(4)电子结构、力学性能及晶格热导率的影响。结果表明:β-Si_(3)N_(4)为热力学稳定结构,Sc掺杂降低了β-Si_(3)N_(4)的稳定性。能带结构、态密度和Mulliken布居分析表明,Sc掺杂降低了β-Si_(3)N_(4)的能带带隙、共价性和离子性,提高了其导电性,这是Sc掺杂降低其稳定性的主要原因。Sc掺杂后β-Si_(3)N_(4)的体模量降低,剪切模量和杨氏模量提高,韧性下降。此外,Sc掺杂使得β-Si_(3)N_(4)在300 K下的晶格热导率提高了20%。
Mechanicalproperty,thermal conductivity and electronic structures of Sc-dopedβ-Si_(3)N_(4)were studied in this work by using the first-principles calculations of plane wave ultra-soft pseudo-potential technology based on the density functional theory(DFT).Results show thatβ-Si_(3)N_(4)is a thermodynamically stable structure,and with Sc doping,the structural stability of the Sc-doped decreases.The results of the band structure,density of states and Mulliken bond population analysis reveal that Sc doping reduces the band gap,the covalent bond and ionic bond strength,and reduces the structural stability of the system.After Sc doping,the bulk modulus and toughness were reduced,but the shear modulus and young modulus were increased.In additions,the lattice thermal conductivity ofβ-Si_(3)N_(4)increased by 20%at 300 K.
作者
龙敏
黄福祥
徐良玉
冷月
杨州
李雪梅
LONG Min;HUANG Fuxiang;XU Liangyu;LENG Yue;YANG Zhou;LI Xuemei(College of Material Science and Engineering,Chongqing University of Technology,Chongqing 400054,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2022年第S02期75-79,共5页
Materials Reports
基金
重庆理工大学研究生创新基金(gzlcx20223035)。
关键词
力学性能
晶格热导率
电子结构
第一性原理
mechanical property
thermal conductivity
electronic structure
first-principles
