无序二元合金(Ni_xCu_(1-x))不同解理面上O吸附对Cu偏析的影响  

Influence of O adsorbed on different surfaces of Ni_xCu_(1-x) on the segregation of Cu

作　　者：张辉[1] 张国英[1] 王瑞丹[1] 周永军[1] 李星[1] 

机构地区：[1]沈阳师范大学物理科学与技术学院,沈阳110034

出　　处：《物理学报》2005年第11期5356-5361,共6页Acta Physica Sinica

基　　金：教育部科学研究重点项目(批准号:99026)资助的课题.~~

摘　　要：应用计算机编程构造出了存在和不存在表面偏析的无序二元合金NixCu1-x(x=0.4)(100)表面及(110)表面的原子集团模型,然后按覆盖度θ=0.5,构造出了O吸附后的原子集团模型,应用Recursion方法计算了O在NixCu1-x(存在偏析和不存在偏析时)无序二元合金(100)和(110)表面吸附的电子结构.由此得出:1)O吸附使合金表面态密度峰降低,带宽加宽,并且表面Ni原子的d电子与吸附质O原子的s,p电子的共价作用比Cu更强烈;2)O吸附在NixCu1-x(x=0.4)(110)表面比(100)表面更稳定;3)O的吸附抑制了Cu在表面富集,且这种作用主要表现在表面一层.The atomic structural models of the（100） and （110） surface of the NixCu1-x disordered binary alloy were set up when surface segregation is considered or not by computer programming. Then the models of the chemisorption of O on both surfaces were set up with the coverage θ = 0.5. The electronic structure of O chemisorbed on the （100） and （110） surfaces of the NixCu1-x disordered binary alloy was calculated （considering and not considering the segregation）. The calculated results show that （1） the chemisorption lowers the surface density of states of the disordered binary alloy, the energy band is widened, and the covalent bonds between the d electron of Ni and the s and p electron of O are stronger than that of Cu, （2） the O adsorbed on the （110） surface is more stable than on the （100） surface, and （3） the chemisorption of O on the surface restricts the surface segregation of Cu and this kind of influence is obvious at the first layer.

关 键 词：化学吸附 表面偏析 Recursion方法 态密度 无序二元合金 表面偏析 表面吸附 Cu Recursion方法 解理面 计算机编程 电子结构 集团模型 

分 类 号：O482.3[理学—固体物理]