First-principles-based embedded atom method for PdAu nanoparticles

Abstract

One of the key problems in studying alloy nanoparticle catalysis is their surface morphology and segregation behavior. We have developed an accurate embedded atom method ͑EAM͒ potential and employed it in the simulation of PdAu metal alloy nanoparticles. The potential was parameterized based on an extensive set of density-functional-theory ͑DFT͒ calculations of metal clusters in addition to bulk-alloy properties. The EAM potential accurately reproduces DFT energies of both bulk PdAu alloys and small nanoparticles. We utilized the developed EAM potential in a Monte Carlo simulation of PdAu nanoparticles ranging from 55-atom ͑ϳ1 nm͒ to 5083-atom particles ͑ϳ4.5 nm͒. The effects of different factors ͑particle size, temperature, and composition ratios͒ on the segregation behavior of PdAu alloy are examined. Our simulation results quantitatively reveal the extent of surface segregation and a strong dependence of surface morphology on the nanoparticle size.

Study of defects in Pd thin films on Au(100) using molecular dynamics

“…The Zhou potential 19 which has an analytic form for the potential fitted to experimental values and the Bin potential 18 which is a modification of the Zhou potential also parameterized to include fitting to density-functional-theory calculations of bulk properties of the Pd-Au alloy and of metal clusters.…”

“…1 we show the GPF energy curve calculated with three effective potentials used in the present work. [18][19][20] It shows the energy cost for a slip over the ͑111͒ plane along the ͓112͔. The energy barrier ␥ us is the lowest value to be overcome for the occurrence of a stacking fault with energy ␥ sf .…”

Development of lattice inversion modified embedded atom method and its applications

“…Lee and Cho [13] extended EAM by introducing a local structural dependent prefactor with three additional parameters to account for the bond characteristics arising from asymmetrical surface atoms. Shan et al [14] reported an extension of EAM potentials applied to alloy nanoparticles by refining the original EAM embedding and cross-pair functionals. Some works have also been done to improve the EAM accuracy by incorporating the Chen-M€ obius lattice inversion [15e19] method into the potential fitting process [20e23].…”

Critical size of transitional copper clusters for ground state structure determination: empirical andab initiostudy

“…In large clusters, electronic shells do not play an important role and the atomic structure effects may be negligible. Empirical methods have been successfully used to investigate the ground state of large clusters [13,14]. In the transitional size clusters, geometrical effects become important so that a condition of minimising the surface area becomes competitive compared to the electronic interaction between the nearest neighbours.…”