Studies of Surface Composition and Phase Transition of Mo-5%Re(1O0)

Abstract

ABSTRACTSurface composition of a clean Mo-5%Re(100) alloy was determined quantitatively by Auger Electron Spectroscopy and X-Ray Photoelectron Spectroscopy. A slight enrichment of Re on the alloy surface was found at and below room temperatures and the result is consistent with the prediction by a graphical approach for segregation. The change of surface composition due to gas contamination and sputtering were also studied. In contrast to the pure Mo(100) surface where a structural phase transition occurs below room temperature, low energy electron diffraction showed no structural change down to 160 K. However, for H, CO, N chemisorptions and C segregation on the alloy surface, LEED patterns similar to the ones observed from a pure Mo(100) surface were observed.