Solid-Liquid Phase Diagrams for Binary Metallic Alloys: Adjustable Interatomic Potentials

摘要

We develop a new approach to determining LJ-EAM potentials for alloys and usethese to determine the solid-liquid phase diagrams for binary metallic alloysusing Kofke's Gibbs-Duhem integration technique combined with semigrandcanonical Monte Carlo simulations. We demonstrate that it is possible toproduce a wide-range of experimentally observed binary phase diagrams (with nointermetallic phases) by reference to the atomic sizes and cohesive energies ofthe two elemental materials. In some cases, it is useful to employ a singleadjustable parameter to adjust the phase diagram (we provided a good choice forthis free parameter). Next, we perform a systematic investigation of the effectof relative atomic sizes and cohesive energies of the elements on the binaryphase diagrams. We then show that this approach leads to good agreement withseveral experimental binary phase diagrams. The main benefit of this approachis not the accurately reproduction of experimental phase diagrams, but ratherto provide a method by which material properties can be continuously changed insimulations studies. This is one of the keys to the use of atomisticsimulations to understand mechanisms and properties in a manner not availableto experiment.