Molecular dynamics simulation of zirconium tungstate amorphization and the amorphous-crystalline interface

JA Greathouse and PF Weck and ME Gordon and E Kim and CR Bryan, JOURNAL OF PHYSICS-CONDENSED MATTER, 32, 085401 (2020).

DOI: 10.1088/1361-648X/ab5377

Classical molecular dynamics (MD) simulations were performed to provide a conceptual understanding of the amorphous-crystalline interface for a candidate negative thermal expansion (NTE) material, ZrW2O8. Simulations of pressure-induced amorphization at 300?K indicate that an amorphous phase forms at pressures of 10?GPa and greater, and this phase persists when the pressure is subsequently decreased to 1 bar. However, the crystalline phase is recovered when the slightly distorted 5?GPa phase is relaxed to 1 bar. Simulations were also performed on a two-phase model consisting of the high-pressure amorphous phase in direct contact with the crystalline phase. Upon equilibration at 300?K and 1 bar, the crystalline phase remains unchanged beyond a thin layer of disrupted structure at the crystalline-amorphous interface. Differences in local atomic structure at the interface are quantified from the simulation trajectories.

Return to Publications page