[SY-F13] Symposium F-13

[SY-F13] In-plane characterization of structural and thermodynamic properties for steps at faceted chemically heterogeneous solid/liquid interfaces

^○Hongtao Liang¹, Brian B. Laird², Mark Asta³, Yang Yang¹ (1.Physics Department and State Key Laboratory of Precision Spectroscopy, School of Physical and Material Science, East China Normal Universit, China, 2.Department of Chemistry, University of Kansas, United States of America, 3.Department of Materials Science and Engineering, UC Berkeley, United States of America)

We present a methodology for studying steps at faceted chemically heterogeneous solid/liquid interfaces based on molecular-dynamics simulations. The methodology is applied to a faceted Al(111)/Pb(liquid) interface yielding a direct calculation of step free energy and extensive atomic-scale characterization for the interfacial layer containing the step. We characterized the step by calculating the in-plane density, potential energy, pressure components and stresses profiles. Main findings include: i) Calculated step free energy is in good agreement with TEM experimental measurement. ii) The step is connecting the interface liquid under tension and the interface solid under compression. iii) Fundamental properties of interface solid and interface liquid show orders of magnitudes difference in comparing with those predicted from the bulk Al-Pb alloy phase diagram. It is hoped that the methodology is extendable to the exploration of complexion equilibria/transitions at grain boundaries.