CAJ | 학술논문

　　为研究氮气在Nb（100）表面吸附过程中的物理机制，采用密度泛函理论和第一性原理方法对Nb（100）表面吸附氮气的功函数、几何结构、吸附能、电子结构和振动频率等性质进行研究。计算结果表明：当分子覆盖度为1.0 ML时，垂直的氮气易于吸附在Nb（100）表面的顶位；当分子覆盖度为0.5 ML时，桥位是氮气吸附于表面的最稳吸附位；当分子覆盖度为0.25 ML时，氮气则基本垂直吸附在顶位。分波态密度的研究发现， Nb（100）表面和氮气之间的相互作用主要通过Nb原子的d轨道与N原子的px， py轨道间的杂化。吸附分子中两氮原子间的振动频率强烈地依赖于其吸附结构，垂直吸附分子的N-N键的振动频率强于倾斜和平行吸附分子的。垂直吸附桥位和顶位的氮分子间原子振动频率分别是1872～2068 cm-1和2173～2204 cm-1。
　　위연구담기재Nb（100）표면흡부과정중적물리궤제，채용밀도범함이론화제일성원리방법대Nb（100）표면흡부담기적공함수、궤하결구、흡부능、전자결구화진동빈솔등성질진행연구。계산결과표명：당분자복개도위1.0 ML시，수직적담기역우흡부재Nb（100）표면적정위；당분자복개도위0.5 ML시，교위시담기흡부우표면적최은흡부위；당분자복개도위0.25 ML시，담기칙기본수직흡부재정위。분파태밀도적연구발현， Nb（100）표면화담기지간적상호작용주요통과Nb원자적d궤도여N원자적px， py궤도간적잡화。흡부분자중량담원자간적진동빈솔강렬지의뢰우기흡부결구，수직흡부분자적N-N건적진동빈솔강우경사화평행흡부분자적。수직흡부교위화정위적담분자간원자진동빈솔분별시1872～2068 cm-1화2173～2204 cm-1。
In order to study the physical mechanism of N2 adsorption on Nb(100) surface, the den-sity functional theory calculations and first principle investigation were performed to investigate the work function , structural properties , adsorption energies , electronic structures , and surface vibra-tional modes of N2 on Nb(100) surface.Results show that the upright N2 prefers to be absorbed on top sites at 1.0 ML coverage, while the bridge site is the most favorable site at 0.5 ML.At 0.25 ML, vertical N2 is absorbed on top sites steadily .Further analyses based on partial density of states reveal that the essential interaction between N2 and metal substrate is the hybridization of Npx , py-orbital and the d-bands of surface niobium atoms .The frequencies of N2 exhibit the expected strong adsorption structure dependence:N2 molecules adsorbed in the vertical structures vibrate faster than those in parallel and tilted structures .In the modes of upright N2 on top and bridge sites , the ad-sorption ranges are 2173-2204 cm-1 and 1 872-2 068 cm-1 , respectively .