First-principles study of the initial stage of aluminum oxidation

An investigation using DFT into the impact of hydrogen on oxygen migration processes during aluminum anodization

“…The radius of O atom is 0.74 Å, whereas the radius of the octahedral and tetrahedral interstitial spheres of the lattice of aluminum were found to be 0.146 a and 0.080 a , respectively, where a is the lattice constant of the crystal of aluminum. 29 Thus, O atoms should easily occupy and remain stable in the octahedral interstitial positions. This could be caused by the formation of solid solution which is related to the electronegativity difference and bonding type between the atoms.…”

“…Existing study had got the result of the migration and activation energy of O atoms on the surface of aluminum, which the energy is large and ion diffusion is difficult. 29 Density functional theory (DFT) has been the most effective tool in condensed matter physics for computing electronic structure and its properties since its inception in the 1960s, when it was initially used to derive the well-known Kohn-Sham (KS) equation under the local density approximation (LDA). Numerous atomic and molecular physics puzzles, including those involving catalytic active sites, 30,31 geometric structure, 32,33 and material electronic structure properties, 34,35 can be resolved with DFT.…”

“…Existing study had got the result of the migration and activation energy of O atoms on the surface of aluminum, which the energy is large and ion diffusion is difficult. 29 …”

Testing the Cabrera–Mott Oxidation Model for Aluminum under Realistic Conditions with Near-Ambient Pressure Photoemission

“…They extended our knowledge down to the “atomistic” level for the mechanisms involved during oxidation. (See, for example, refs − for the specific case of Al oxidation.) Nevertheless, modern theoretical works aim to bridge the gap with the key parameters of the CM model.…”

“…In recent years, gas-phase oxidation studies have greatly benefitted from implementing in situ, real-time techniques such as NAP-XPS. − As a prerequisite to XPS measurements, we first had to clarify the model’s thermodynamic grounds and discriminate what spectroscopic proxies should be monitored. We have considered Al oxidation in O 2 because of its historical role in establishing the oxidation models ,, and because it keeps attracting considerable attention both experimentally − and theoretically. ,,− ,, Aluminum is also the material of choice in the fabrication of Josephson junction qubits, for which the oxidation of the metal is a vital issue . The Al/AlO x /Al junctions are often fabricated by exposing the metallic surface to O 2 (at room temperature in the mbar range) .…”