A study of electronic structures of Pt3M (M=Ti,V,Cr,Fe,Co,Ni) polycrystalline alloys with valence-band photoemission spectroscopy.
The surface valence-band densities of states (DOS) of Pt(3)M (M=Ti,V,Cr,Fe,Co,Ni) polycrystalline alloys were investigated with ultraviolet photoemission spectroscopy. Upon annealing the ion-sputter-cleaned alloys at high temperatures, the observed valence-band DOS spectra clearly show the modified electronic structures on the surfaces suggesting the surface segregation of Pt as predicted in thermodynamic models. The measured d-band centers and widths for the annealed alloy surfaces show qualitatively the same trend as predicted by density-functional-theory calculations based on the model of a Pt "skin" on the topmost surface layer and a subsurface layer enriched in the 3d transition metal.
Mun
Bongjin Simon
BS
Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA. bsmun@lbl.gov
Watanabe
Masamitsu
M
Rossi
Massimiliano
M
Stamenkovic
Vojislav
V
Markovic
Nenad M
NM
Ross
Philip N
PN