Thermal surface free energy and stress of iron

• Published in: Scientific reports Vol. 5; no. 1; p. 14860
• Main Authors: Schönecker, Stephan, Li, Xiaoqing, Johansson, Börje, Kwon, Se Kyun, Vitos, Levente
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 06-10-2015; Nature Publishing Group
• Subjects: 639/301/1034/1038; 639/301/119/544; 639/766/119/997; Anisotropy; Approximation; Energy; Free energy; Humanities and Social Sciences; Iron; multidisciplinary; Phase transitions; Physics; Science; Surface properties; Temperature; Temperature effects; Vibrations
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep14860

Absolute values of surface energy and surface stress of solids are hardly accessible by experiment. Here, we investigate the temperature dependence of both parameters for the (001) and (110) surface facets of body-centered cubic Fe from first-principles modeling taking into account vibrational, electronic and magnetic degrees of freedom. The monotonic decrease of the surface energies of both facets with increasing temperature is mostly due to lattice vibrations and magnetic disorder. The surface stresses exhibit nonmonotonic behaviors resulting in a strongly temperature dependent excess surface stress and surface stress anisotropy.