摘要
采用基于密度泛函理论的第一原理方法,研究了Ti-V系合金Ti 3 V,TiV和TiV 3的晶体结构,电子结构及力学性质.结果表明,TiV 3结构最稳定,其次是TiV,而Ti 3 V稳定性最弱,但是,Ti 3 V形成能力最强.三种合金的自间隙构型中,与Ti的自间隙构型相比,更容易形成V的自间隙构型;不管是Ti自间隙还是V自间隙,TiV 3的自间隙形成能均最大.力学性质的计算表明:三种合金均满足力学稳定性标准,且都为韧性材料;体模量及硬度计算表明,TiV 3的硬度最高,其次是TiV,Ti 3 V的硬度最低,这与自间隙能的计算结果一致.电子结构计算表明:在费米能级处,三种合金均主要由Ti,V的p,d轨道电子提供态密度,TiV 3合金电子结构最稳定.差分电荷密度计算表明:在Ti 3 V合金中,金属性强于共价性.在Ti 3 V,TiV,TiV 3三种合金中,金属性逐渐减弱,共价性逐渐增强,合金变得稳定.
The crystal structures,electronic structures and mechanical properties of Ti 3 V,TiV and TiV 3 of Ti-V alloys were studied by using the first principle method based on density functional theory.The results show that TiV 3 has the most stable structure,followed by TiV,Ti 3 V has the weakest stability,but Ti 3 V has the strongest formation ability.Compared with the self-interstitial configuration of Ti,the self-interstitial configuration of V is easier to be formed.Whether it is Ti self-interstitial or V self-interstitial,the formation energy of self-interstitial of TiV 3 is the largest.The calculation of mechanical properties shows that all three alloys meet the mechanical stability standard and are ductile materials.The calculation of volume modulus and hardness shows that TiV 3 has the highest hardness,TiV follows,Ti 3 V has the lowest hardness,which is consistent with the calculation results of self-interstitial energy.The electronic structure calculation shows that at the Fermi level,the state densities of the three alloys are mainly provided by the p and d orbitals of Ti and V,and the electronic structure of the TiV 3 alloy is the most stable.Differential charge density calculation shows that metallic properties are stronger than covalency in Ti 3 V alloy.In Ti 3 V,TiV and TiV 3 alloys,the metallicity decreases and the covalency increases gradually,and the alloy becomes stable.
作者
刘晓瑞
陈芳芳
程超
王逊
孙嘉兴
刘艳侠
LIU Xiao-Rui;CHEN Fang-Fang;CHENG Chao;WANG Xun;SUN Jia-Xing;LIU Yan-Xia(College of Physics,Liaoning University,Shenyang 110036,China;College of Science,Shenyang Jianzhu University,Shenyang 110168,China)
出处
《原子与分子物理学报》
CAS
北大核心
2020年第4期625-631,共7页
Journal of Atomic and Molecular Physics
基金
国家重点基础研究发展计划(2016YFB0701304)。
关键词
第一原理
Ti-V系合金
晶体结构
力学性质
电子结构
First principle
Ti-V system alloys
Crystal structure
Mechanical property
Electronic structure
