Results for “Cu3Pt”

DOE OSTI2020

Materials Data on Cu3Pt by Materials Project

PtCu3 is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Pt is bonded to twelve equivalent Cu atoms to form PtCu12 cuboctahedra that share corners with twelve equivalent PtCu12 cuboctahedra, edges with twenty-four equivalent CuCu8Pt4 cuboctahedra, faces with six equivalent PtCu12 cuboctahedra, and faces with twelve equivalent CuCu8Pt4 cuboctahedra. All Pt–Cu bond lengths are 2.63 Å. Cu is bonded to four equivalent Pt and eight equivalent Cu atoms to form CuCu8Pt4 cuboctahedra that share corners with twelve equivalent CuCu8Pt4 cuboctahedra, edges with eight equivalent PtCu12 cuboctahedra, edges with sixteen equivalent CuCu8Pt4 cuboctahedra, faces with four equivalent PtCu12 cuboctahedra, and faces with fourteen equivalent CuCu8Pt4 cuboctahedra. All Cu–Cu bond lengths are 2.63 Å.

36 MATERIALS SCIENCE↗

DOE OSTI2022

Effect of surface segregation on the oxidation resistance of Cu 3 Pt ( 100 )

Alloying element segregation often occurs under a reactive environment but its interplay with the subsequent surface oxidation of the alloy remains unclear. Using synchrotron-based ambient-pressure x-ray photoelectron spectroscopy, we dynamically monitor the surface segregation in Cu 3 Pt(100) in response to temperature and oxygen gas. Vacuum annealing leads to surface segregation of Cu along with the enrichment of Pt in the subsurface region. Upon switching to the O 2 atmosphere, dissociative chemisorption of oxygen does not change the surface segregation profile from that under the vacuum annealing condition. A stepwise increase in the oxygen pressure results in the transformation pathway of Cu → Cu 2 O → CuO, in which the selective oxidation of Cu gives rise to further accumulation of Pt underneath the oxide/alloy interface that hinders the supply of Cu from the bulk to the oxide/alloy interface, thereby leading to the termination of the surface oxidation after the Cu 2 O → CuO conversion is completed. This differs from the transformation pathway of Cu → Cu 2 O → Cu 2 O/CuO for the oxidation of pure Cu and Cu-Au alloys, in which the oxidation of Cu continues and the Cu 2 O/CuO bilayer growth is constantly maintained. Furthermore, these key differences provide useful insight into alloy design for controlling the surface properties such as corrosion resistance and catalytic performance of Cu base alloys.

36 MATERIALS SCIENCE↗