非金属空位对TiN_(x)电子结构及导电性能影响的第一性原理研究  

Effect of Nonmetallic Vacancies on Electronic Structure and Conductivity of TiN_(x):First-Principles Study

作　　者：赵蒙 周晖[1] 何延春[1] 贵宾华 汪科良 Zhao Meng;Zhou Hui;He Yanchun;Gui Binhua;Wang Keliang(Science and Technology on Vacuum Technology and Physical Laboratory,Lanzhou Institute of Physics,Lanzhou 730000,China)

机构地区：[1]兰州空间技术物理研究所真空技术与物理重点实验室,甘肃兰州730000

出　　处：《稀有金属材料与工程》2024年第11期3205-3210,共6页Rare Metal Materials and Engineering

基　　金：甘肃省青年科技基金(22JR5RA786);甘肃省自然科学基金(23JRRA1353)。

摘　　要：TiN涂层因良好的耐腐蚀、导电性能在金属双极板改性领域被广泛应用。TiN沉积过程中易受制备条件影响而形成非金属空位,进而影响涂层性能。因此,本研究利用第一性原理方法计算了含有不同非金属空位量的TiN_(x)体系的电子结构,展开了非金属空位对各TiN_(x)体系的晶体结构、能带结构、态密度、自由电子相对浓度及电荷布居影响研究。分析结果表明,随着非金属空位的形成,各TiN_(x)体系稳定性逐渐下降,非金属空位形成能逐渐升高。经计算,各TiN_(x)体系的自由电子相对浓度大小排序如下:TiN_(0.25)>TiN>TiN_(0.5)>TiN_(0.75)。TiN_(x)体系的导电能力主要由Ti原子3d轨道状态的金属化、N原子2p轨道贡献的减少以及N原子缺失导致晶胞体积减小等3个因素共同影响。TiN coatings are widely used in metal bipolar plate modification due to their good corrosion resistance and electrical conductivity.The TiN deposition process is susceptible to the preparation conditions to from non-metallic vacancies,thus affecting the coating properties.Therefore,in this study,the electronic structures of TiN_(x)systems containing different amounts of non-metallic vacancies were calculated using the first-principle method,and the effect of non-metallic vacancies on the crystal structure,energy band structure,density of states,relative concentration of free electrons,and charge spreading of each TiN_(x)system was investigated.The results show that with the formation of non-metallic vacancies,the stability of each TiN_(x)system gradually decreases and the non-metallic vacancy formation energy gradually increases.The relative concentration of free electrons of each TiN_(x)system is calculated to be in the following order:TiN_(0.25)>TiN>TiN_(0.5)>TiN_(0.75).The electrical conductivity of the TiN_(x)system is mainly affected by the combination of three factor:the metallization of the 3d orbital state of the Ti atoms,the reduction of the contribution of the N atoms to the 2p orbital,and the decrease in the volume of the crystal cell due to the deletion of the N atoms.

关 键 词：TiN_(x) 非金属空位 第一性原理 电子结构 导电性能 

分 类 号：TQ174.758[化学工程—陶瓷工业]