Mechanism for Limiting Thickness of Thin Oxide Films on Aluminum
Journal article, 2014

A first-principles account of the observed limiting thickness of oxide films formed on aluminum during oxidizing conditions is presented. The results uncover enhanced bonding of oxygen to thin alumina films in contact with metallic aluminum that stems from charge transfer between a reconstructed oxide-metal interface and the adsorbed molecules. The first-principles results are compared with the traditional Cabrera-Mott (CM) model, which is a classical continuum model. Within the CM model, charged surface oxygen species and metal ions generate a (Mott) potential that drives oxidation. An apparent limiting thickness is observed as the oxidation rate decreases rapidly with film growth. The present results support experimental estimates of the Mott potential and film thicknesses. In contrast to the CM model, however, the calculations reveal a real limiting thickness that originates from a diminishing oxygen adsorption energy beyond a certain oxide film thickness.

Author

J. D. Baran

Henrik Grönbeck

Chalmers, Applied Physics, Chemical Physics

Competence Centre for Catalysis (KCK)

Anders Hellman

Chalmers, Applied Physics, Chemical Physics

Competence Centre for Catalysis (KCK)

Physical Review Letters

0031-9007 (ISSN) 1079-7114 (eISSN)

Vol. 112 14

Areas of Advance

Nanoscience and Nanotechnology (2010-2017)

Transport

Energy

Materials Science

Subject Categories

Physical Sciences

Infrastructure

C3SE (Chalmers Centre for Computational Science and Engineering)

DOI

10.1103/PhysRevLett.112.146103

More information

Created

10/7/2017