Capillary wave analysis of rough solid-liquid interfaces in nickel

Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt (DLR) 51170 Köln, Germany, EU

^a juergen.horbach@dlr.de

Received: 7 November 2010
Accepted: 12 January 2011

Abstract

Crystal-liquid interfaces in nickel are investigated by molecular-dynamics computer simulations. Inhomogeneous systems of size L_x×L_y×L_z with L_z = 5L_y are prepared where the crystal fcc phase at different orientations coexists with the liquid phase, separated by planar interfaces in the xy-plane. The lateral dimensions are varied, using two different geometries with L_x = L_y and with L_y ≫ L_x. In the framework of capillary wave theory (CWT), anisotropic interfacial stiffnesses and tensions are determined using different predictions of CWT with respect to the spectrum, finite-size broadening and different geometries. From a parameterization in terms of cubic harmonics up to 8th order, the anisotropic interfacial free energy is obtained.