The influence of impurities on segregation of the (110) surface of O/RhxPt1-x alloy system

Abstract

The atomic cluster models of (110) surface of RhxPt1-x disordered binary alloy were constructed under the condition that there is interaction between adsorption and segregation. The coverage of O is 0.5. Also，the models that may have an impact on the alloy debased with Cu，Ni and W were set up by computer respectively. It followed that impurities replaced every Rh which should be the nearest neighbor of O. The environment sensitive inlaid energy (EESE) and the electronic structure of the alloy surface doped with Cu，Ni and W was calculated by recursion method. The results of EESE show that, the influence of Ni，Cu and W on Rh-Pt alloy are all to reverse the segregation of the alloy surface. Furthermore，Ni is the most effective imupurity，and then Cu and W. Doped with impurities Cu，Ni and W，the covalent interaction between Rh and O is reduced，which reverses the surface segregation，so Pt segregates on the surface.