掺Cu对O吸附Rh_xPt_(1-x)合金(110)表面偏析的影响  

Influence of Cu on Segregation of (110) Surface of Rh_xPt_(1-x) Alloy with O Adsorbed

作　　者：何君琦[1] 张辉[1] 王丹[1] 徐海涛 

机构地区：[1]沈阳师范大学物理科学与技术学院,辽宁沈阳110034 [2]海城市高级中学物理组,辽宁鞍山114200

出　　处：《沈阳师范大学学报（自然科学版）》2007年第2期163-166,共4页Journal of Shenyang Normal University:Natural Science Edition

基　　金：国家自然科学基金资助项目(50571071)

摘　　要：应用计算机编程构造出了考虑和不考虑吸附与偏析相互作用情况下无序二元合金RhxPt1-x(110)表面的原子集团模型(O的覆盖度为0.5).考虑掺Cu对合金表面产生影响的原子集团模型,Cu的掺入采用替位式,即将O的最近邻的Rh替换为Cu.应用Recursion方法计算了掺Cu对O吸附情况下RhxPt1-x无序二元合金(110)表面的电子结构,由此得出:1)Rh0.7Pt0.3合金表面存在着Rh偏析,掺Cu使合金表面偏析情况发生逆转;2)掺Cu后,Cu使Rh与O的共价相互作用减弱,进而降低了合金表面的总态密度.The atomic group models of （110） surface of RhxPt1-x disordered binary alloy were set up by computer under the conditions of whether consider the interaction of adsorption and segregation or not. The coverage of O is 0.5. Also, the Cu-doped models were set up. It followed that Cu replaced Rh which should be the nearest neighbor of O. The electronic structure of this alloy surface was calculated. The results show that： 1） Rh is segregated on the surface of Rh0.7Pt0.3 alloy. The alloy surface that Cu-doped can reverse the segregation of the alloy surface. 2） After doping with Cu, the covalent function between Rh and O is reduced and then lower the total density of state.

关 键 词：化学吸附 表面偏析 Reeursion方法 

分 类 号：O647[理学—物理化学]