Investigation of composition related structural and dynamic properties of binary and ternary metal nanoalloys

Nanoalloys are of practical and scientific significance from the viewpoint of understanding fundamental electrical, magnetic, optical, catalytic, thermal and mechanical properties of nanoscale materials. Especially in catalysis applications, nanoalloys can be of great interest. In this study, the initial geometry of icosahedron motif consisting of N=19, 23, 26, 38 and 55 atoms Cu-Ag-Au, Pt-Al-Cu and Ni-Al-Cu ternary nanoalloys and initial geometry of decahedron motif consisting of N=55 and 71 atoms Pt-Al-Cu ternary nanoalloys were investigated. This theoretical investigation of Cu-Ag-Au, Pt-Al-Cu and Ni-Al-Cu ternary nanoalloys was carried out by modelling interatomic interactions with the Gupta many-body potential energy function. Geometry optimization of nanoalloys was obtained by Monte Carlo simulation method using Basin Hopping algorithm. The optimization results showed that atoms were mixed in Cu-Ag-Au and Pt-Al-Cu, whereas were segregated in Ni-Al-Cu nanoalloys. Excess energy analyzes were performed to investigate the stability of nanoalloys. The melting behavior of the most stable nanoalloys found by excess energy analyzes were investigated using the Molecular Dynamics Simulation method. MD simulations of Cu-Ag-Au, Pt-Al-Cu and Ni-Al-Cu nanoalloys have been carried out at low and high temperatures to study solid and liquid properties of nanoalloys. The melting transition of nanoalloys analyzed by means of caloric curve and Lindemann index. Structural evolutions and dynamical behaviors of nanoalloys in melting process investigated with radial distribution function, root mean square displacement (RMSD) and Polyhedral template matching (PTM) analyses. The simulation results showed that varying the atomic type and atom number in composition gives rise to a change in melting temperatures.