IFISUR   23398
INSTITUTO DE FISICA DEL SUR
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Optimization of a platinum-nickel surface by DFT calculations
Autor/es:
E. TORTORELLA; S. ULACCO; S. SIMONETTI
Reunión:
Congreso; 3rd World Congress on Integrated Computational Materials Engineering; 2015
Resumen:
The development of modern theoretical surface science provides an opportunity to investigate structures on the atomic scale with useful applications in industrial technologies. From the technological point of view, bimetallic surfaces have recently attracted great attention by their activities as industrial materials in novel applications. Platinum and nickel are ones of the most versatile heterogeneous metals catalysis. Its chemical stability makes it a very convenient election in a lot of applications. In this work, a Pt-Ni(111) surface has been optimized with calculations carried out in the framework of the Density Functional Theory (DFT) using the Vienna Ab-initio Simulation Package (VASP). In this code plane wave basis sets are used to solve the Kohn Sham equations. Electron exchange and correlation effects are described by the generalized gradient approximation (PBE). The electron ion interactions are described by the projector-augmented wave (PAW) potentials. The fixed convergence of the plane-wave expansion was obtained with cut-off energy of 300eV. This value is based on a previous test, which calculation error was lower than 0.01eV. The two dimensional Brillouin integrations were full filled on a (3x3x1) Monkhorst-Packgrid previously tested. In order to evaluate the magnetic properties of the systems, the computations were performed at the spin-polarized level. The Pt-Ni(111) surface of FCC stacking layered structure was represented with a periodically repeated slab containing five layers of atoms separated in the normal direction by a vacuum region. The width of this gap was optimized to avoid the interaction between slabs. The lattice constants were also optimized.