| Abstract
| - With the aid of ab initio calculations, an n-body potential of the Ni−Nb system is constructed under theFinnis−Sinclair formalism and the constructed potential is capable of not only reproducing some static physicalproperties but also revealing the atomistic mechanism of crystal-to-amorphous transition and associated kinetics.With application of the constructed potential, molecular dynamics simulations using the solid solution modelsreveal that the physical origin of crystal-to-amorphous transition is the crystalline lattice collapsing while thesolute atoms are exceeding the critical solid solubilities, which are determined to be 19 atom % Ni and 13atom % Nb for the Nb- and Ni-based solid solutions, respectively. It follows that an intrinsic glass-formingability of the Ni−Nb system is within 19−87 atom % Ni, which matches well with that observed in ion beammixing/solid-state reaction experiments. Simulations using the Nb/Ni/Nb (Ni/Nb/Ni) sandwich models indicatethat the amorphous layer at the interfaces grows in a layer-by-layer mode and that, upon dissolving soluteatoms, the Ni lattice approaches and exceeds its critical solid solubility faster than the Nb lattice, revealingan asymmetric behavior in growth kinetics. Moreover, an energy diagram is obtained by computing the energeticsequence of the NixNb100-x alloy in fcc, bcc, and amorphous structures, respectively, over the entire compositionrange, and the diagram could serve as a guide for predicting the metastable alloy formation in the Ni−Nbsystem.
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