氮掺杂ZrC和TaC结构和电子性质的第一性原理研究  

First-Principles Study on the Structure and Electronic Properties of Nitrogen-Doped ZrC and TaC

作　　者：刘尚 刘士余 张硕鑫 严达利 余浅 任海涛 于彬 李德军 LIU Shang;LIU Shi-Yu;ZHANG Shuo-Xin;YAN Da-Li;YU Qian;REN Hai-Tao;YU Bin;LI De-Jun(School of Physics and Materials Science,Tianjin Normal University,Tianjin 300387,China)

机构地区：[1]天津师范大学物理与材料科学学院,天津300387

出　　处：《现代技术陶瓷》2021年第4期248-255,共8页Advanced Ceramics

基　　金：国家自然科学基金(61601327,51772209,11604244);天津市自然科学基金(17JCQNJC01000);天津师范大学创新基金(52XC1504)。

摘　　要：为了研究氮(N)掺杂对难熔金属碳化物ZrC和TaC的影响,本文运用第一性原理超原胞方法(SC)和虚晶近似方法(VCA)进行了研究。计算了掺杂不同浓度N原子的ZrC_(1-x)Nx和TaC_(1-x)N_(x),(0≤X≤1)难熔金属碳氮化物的形成能、晶格常数、体积以及电子态密度。形成能计算结果表明ZrC_(1-x)Nx和TaC_(1-x)N_(x)的稳定性随氮浓度的增大而增强;晶格常数和体积随氮浓度的增大而减小,结构也越来越稳定;氮掺杂导致的电子态密度在深能级处的新峰随着氮浓度的增大而变高,也表明结构更稳定。此外,比较相同N浓度下的ZrC_(1-x)Nx和TaC_(1-x)N_(x),发现ZrC_(1-x)Nx的形成能更低,因此掺杂相同浓度的N时ZrC_(1-x)Nx更稳定。To investigate the influence of impurity of nitrogen(N)in the cubic ZrC and TaC,first-principle calculations with supercell(SC)method and virtual crystal approximation(VCA)method were performed in the present study.The formation energy,lattice constant,volume and electronic density of states of ZrC_(1-x)Nxand TaC_(1-x)N_(x),(0≤X≤1)compounds doped with different concentrations of nitrogen atoms were calculated respectively.The formation energy shows that the stability of ZrC_(1-x)Nx and TaC_(1-x)N_(x)increases with the increase of nitrogen concentration.The lattice constant and volume decrease with the increase of nitrogen concentration,which indicate the structure becomes more and more stable.The new peak of density of state(DOS)at the deep energy level becomes higher with the increase of nitrogen,which also suggests that the structure is more stable with the increase of nitrogen.In addition,comparing the stability of ZrC_(1-x)Nx and TaC_(1-x)N_(x)at the same N concentration,it was found that the impurity formation energy of ZrC_(1-x)Nx was lowerthan that of TaC_(1-x)N_(x)so the ZrC_(1-x)Nx was more stable.

关 键 词：金属碳氮化物 第g性原理 杂质形成能 电子结构 

分 类 号：O641[理学—物理化学]