Atomistic simulations of fcc Pt{sub 75}Ni{sub 25} and Pt{sub 75}Re{sub 25} cubo-octahedral nanoparticles

Conference · Tue Mar 30 04:00:00 EST 2004

OSTI ID:822978

Wang, Guofeng ^[1]; Van Hove, M A; Ross, P N; Baskes, M I

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1. LBNL Library

We have developed interatomic potentials for Pt-Ni and Pt-Re alloys within the modified embedded atom method (MEAM). Furthermore, we applied these potentials to study the equilibrium structures of Pt75Ni25 and Pt75Re25 nanoparticles at T=600 K using the Monte Carlo method. In this work, the nanoparticles are assumed to have disordered fcc cubo-octahedral shapes (terminated by {l_brace}111{r_brace} and {l_brace}100{r_brace} facets) and contain from 586 to 4033 atoms (corresponding to a diameter from 2.5 to 5 nm). It was found that, due to surface segregation, (1) the Pt75Ni25 nanoparticles form a surface-sandwich structure: the Pt atoms are enriched in the outermost and third atomic shells, while the Ni atoms are enriched in the second atomic shell; (2) the equilibrium Pt75Re25 nanoparticles adopt a core-shell structure: a Pt-enriched shell surrounding a Pt-deficient core.

• Research Organization: Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, CA (US)
• Sponsoring Organization: USDOE Director. Office of Science. Basic Energy Sciences, Los Alamos National Laboratory. Contract W-7405-ENG-36 (US)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 822978
• Report Number(s): LBNL--54829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALLOYS
ATOMS
ELECTRONIC STRUCTURE
MONTE CARLO METHOD
PT-NI AND PR-RE NANOPARTICLES CATALYSIS
SEGREGATION