Dresden 2014 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 84: Nanotribology
O 84.6: Vortrag
Donnerstag, 3. April 2014, 17:15–17:30, WIL B321
Adhesion and material transfer between contacting Al and TiN surfaces from first principles — •Gregor Feldbauer1,2, Michael Wolloch1,2, Peter Mohn1, Josef Redinger1, and Andras Vernes1,2 — 1Vienna University of Technology, Gusshausstrasse 25-25a/134, 1040 Vienna, Austria — 2Austrian Center of Competence for Tribology, 2700 Wiener Neustadt, Austria
Contacts of surfaces at the atomic length scale are of fundamental interest for a better understanding of nanotribological processes, which are crucial in modern applications from nanoindentation or AFM/FFM to nanotechnologies applied in NEMS/MEMS.
A series of density functional theory (DFT) simulations was performed to investigate the approaching, contact and subsequent separation of two atomically flat surfaces consisting of various materials. Here, aluminum (Al) and titanium-nitride (TiN) slabs were chosen as a model system representing the interaction between soft and hard materials. The approaching and separation were simulated by moving one slab in discrete steps and allowing for electronic and ionic relaxations after each step. Various configurations of the interface were analyzed by considering (001), (011) and (111) surface orientations as well as several alignments of surfaces. The performed simulations revealed the influences of these aspects on the adhesion, equilibrium distance, charge distribution and material transfer. Material transfer in particular was observed for configurations where the interface is stronger than the softer material in the system, in the sense that the adhesion energy was found larger than the energy cost to remove surface atoms.