ZrC(111)弛豫表面电子结构及其吸附氢的理论研究

采用第一性原理的方法对ZrC（111）清洁和氢吸附表面的电子结构进行了研究 。构型优化结果表明，从表面深入到体相一定深度，层间距存在交替“收缩”和“ 扩张”的现象，其紧邻E_F以下的DOS峰对应于活性表面态，主要成分为表面Zr原子 4d_(xz)/d_(yz)轨道；与理想表面相比，表面弛豫对该表面态影响不大。对于氢吸 附表面，计算结果表明氢原子倾向于吸附在表面孔洞上方位置（正对着第三层Zr原 子），此时H的1s态从体相的电子态中分离出来。此外，本文中H/ZrC（111）和 H/NbC（111）体系的H 1s诱导态变化进行了解释，并对清洁的吸附表面的芯能级位 移以及功函的变化进行了探讨。

Theoretical Study on the Electronic Structures of the Clean and Hydrogen-adsorbed ZrC(111) Surfaces

Using the first-principles method,the electronic structures of clean and hydrogen-adsorbed ZrC(111) surfaces have been s tudied. The results of the geometrical optimization indicate that, for the clean surface, the spacings between the adjacent layers are contracted and expanded a lternately from the surface to the bulk within certain layers. The main componen ts of the surface state in DOS located near EF are 4dxz/d yz orbitals of the surface Zr atoms, and compared to the ideal surface, th e relaxation of the surface has little influence on this state. For the hydrogen -adsorbed surface, the calculated results show that the hydrogen atoms are pref erably adsorbed on the surface hollow sites in which the third layer Zr atoms si t directly below them, and in this case, the H 1s-induced state is separated fr om the bulk states. In addition, the variation of H 1s-induced state is explain ed by comparing with the H/NbC(111) system, and the discussions about the surfac e core-level shifts and the surface work functions are also presented in the pa per.