Solid-State Amorphization Observed in the Equilibrium-Immiscible Cu−Re System by Molecular Dynamics Simulations

Abstract

Assisted by ab initio calculations, an n-body Cu-Re potential is first constructed for the equilibrium-immiscible Cu-Re system under the second moment approximation of a tight-binding scheme. The proven realistic Cu-Re potential is then applied to perform the molecular dynamics simulations using the Cu-Re sandwich model. The simulations reveal that the interfacial free energy stored in the Cu/Re interfaces plays an important role in facilitating the spontaneous solid-state amorphization and that the amorphous interlayer grows in a layer-by-layer mode featuring an asymmetric behavior, i.e., the growth of the amorphous interlayer advances faster toward the Cu lattice than toward the Re direction. It is also found that with increasing the simulation time, the growth speed of the amorphous interlayer gradually slows down and eventually becomes zero when the interlayer reaches a thickness of about 1.47 nm. Interestingly, according to a recently proposed thermodynamic and kinetic model, the maximum thickness of the growing amorphous layer is limited by the available interfacial free energy and in the Cu-Re system, it is estimated to be around 1.35 nm, which is comparable with that observed from the simulations.

Ordered Structures in Rhenium Binary Alloys from First-Principles Calculations

“…Hexagonal Fe/Re multilayer structures were studied due to their peculiar magnetic properties . Amorphization processes in the equilibrium immiscible Cu−Re system and solid solution structures in the Re−Ti system were also investigated using ab initio calculations. Rhenium’s importance as a catalytic agent and the recent increased interest in intermetallic catalysts have led to DFT studies of its surface and nanoparticle properties, as well as of some alloys and surface alloys with platinum group metals (PGMs). − ,, These studies emphasize the need to evaluate the stability of new potential alloy catalysts.…”

Proposed thermodynamic method to predict the glass formation of the ternary transition metal systems

“…Up to now, several empirical criteria and models have been proposed to predict the glass forming range/ability (GFR/GFA) of a metal system. [3][4][5][6][7][8][9] However, most of the proposed criteria are only suitable for the binary alloy systems and some of them can only be used to measure the GFA of an alloy system, in which metallic glasses have already been obtained. 10 Recently, based on Miedema's model, Xia et al proposed the parameter g* to describe the GFA of the binary alloys and it works quite well.…”