Structure of liquid Al and Al₆₇Mg₃₃ alloy: comparison between experiment and simulation

Abstract

We report data on the structure of liquid Al and an Al₆₇Mg₃₃ alloy obtained from state-of-the-art X-ray diffraction experiments and ab initio molecular dynamics (AIMD) simulations. To facilitate a direct comparison between these data, we develop a method to elongate the AIMD pair correlation function in order to obtain reliable AIMD structure factors. The comparison reveals an appreciable level of discrepancy between experimental and AIMD liquid structures, with the latter being consistently more ordered than the former at the same temperature. The discrepancy noted in this study is estimated to have significant implications for simulation-based calculations of liquid transport properties and solid–liquid interface kinetic properties.

Keywords:

• liquid metals
• molecular dynamic simulations
• X-ray diffraction

Funding

Work at the Ames Laboratory was supported by the Department of Energy, Office of Basic Energy Sciences [Contract number DE-AC02-07CH11358]. The high-energy X-ray work at the MUCAT sector of the APS was supported by the US Department of Energy, Office of Science and Basic Energy Sciences [Contract number DE-AC02-06CH11357]. MA acknowledges support from the Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division, of the US Department of Energy (DOE) [Contract number DE-FG02-06ER46282].