(上海交通大學(xué) 材料科學(xué)與工程學(xué)院，上海 200240)
摘 要: 采用基于密度函數(shù)理論的贗勢平面波方法和廣義梯度近似對TiB2和TiB化合物的彈性性質(zhì)和電子結(jié)構(gòu)進(jìn)行了理論計算，并用Voigt-Reuss-Hill方法計算得到多晶體的彈性模量和切變模量。結(jié)果表明：TiB2和TiB的彈性模量分別為599 GPa和443 GPa，切變模量分別為268.5 GPa和193.5 GPa，Pugh 定律和泊松比等經(jīng)驗判據(jù)表明TiB2比TiB脆性更大；并從這兩種化合物的電子結(jié)構(gòu)對其彈性性質(zhì)的差異進(jìn)行了討論。
關(guān)鍵字: 彈性性質(zhì)；電子結(jié)構(gòu)；第一性原理
（School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China）
Abstract:First-principles calculations were carried out to investigate the elastic properties and electronic structure of TiB2 and TiB, using the method of ultrasoft pseudopotential within the generalized gradient approximation based on density functional theory. The moduli of the polycrystals for TiB2 and TiB were calculated from the theoretical elastic constants by Voigt-Reuss-Hill averaging scheme. The calculated results of elastic properties agree well with the experimental values and those calculated in the literature. Based on several empirical criterions of Pugh rule and Poisson’s ratio ν, TiB2 and TiB are brittle in nature, and the brittleness of TiB2 is higher than that of TiB. The difference in elastic properties between TiB2 and TiB is discussed with their electronic structures.
Key words: elastic properties; electronic structure; first-principles
