Thermodynamically accessible titanium clusters Ti_N, N = 2–32

We have performed a genetic algorithm search on the tight-binding interatomic potential energy surface (PES) for small TiN (N = 2–32) clusters. The low energy candidate clusters were further refined using density functional theory (DFT) calculations with the PBEsol exchange–correlation functional and evaluated with the PBEsol0 hybrid functional. The resulting clusters were analysed in terms of their structural features, growth mechanism and surface area. The results suggest a growth mechanism that is based on forming coordination centres by interpenetrating icosahedra, icositetrahedra and Frank–Kasper polyhedra. We identify centres of coordination, which act as centres of bulk nucleation in medium sized clusters and determine the morphological features of the cluster

Effect of alloying on β2-ordered FeAl with Pd and Ir for high-temperature application and ductility enhancement

Β2-ordered FeAl and Fe3Al composition amongst other various compounds of transition metals and aluminium compositions have been of significance to researchers for application in industries for steel-IT coating purposes due to their well-adherent protective oxide layer that forms on the surface of such alloys at the metal/gas interface. We employed Cluster expansion (CE) technique to predict meta-stable and stable compositions of Fe1-XPd/IrXAl ternary. A Cluster Expansion phase diagram was predicted, with five stable Fe1-XPdXAl structures and three stable Fe1-XIrXAl structures having the lowest formation energies, respectively. Employed a first-principles approach to predict the mechanical properties, with four and two Pd and Ir ternary doped ductile structures and DMol3 technique to determine temperature dependence dynamical properties, that is, the binding energy of Fe50Al50, FePdAl2 and FeIrAl2 at various temperatures. Our findings showed that doping on FeAl with Pd and Ir significantly enhanced the binding energy that more energy would be required to disassemble the particles of the Ir system into individual parts; the hardness and ductility of the material for high-temperature application component coating for steel-IT superior protection