Dresden 2026 – scientific programme

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O: Fachverband Oberflächenphysik

O 94: Oxides and insulators: Adsorption and reaction of small molecules

O 94.11: Talk

Friday, March 13, 2026, 12:15–12:30, HSZ/0204

Molecular Dynamics Simulation of Impingment of Atomic Oxygen on Alumina and Silica Surfaces — Stephen Hocker, Hansjörg Lipp, Aahmed Kassem, Ricco Isele, Leonidas Simitsis, and •Johannes Roth — Institute for Functional Matter and Quantum Technologies (FMQ), University Stuttgart, Germany

Atomic oxygen (AO) impinging on satellite surfaces in very low earth orbit (VLEO) transfers momentum and energy, leading to material degradation and drag forces. To be able to counteract these effects, we investigate the impact mechanisms of AO on alumina (Al2O3) and silica (SiO2) surfaces. In this talk we give an overview of our activities: Using molecular dynamics (MD) simulations with classical force fields, we study material stability, angular distributions of reflected particles, and adsorption rates. Our findings indicate that bare Al2O3 does not degrade under AO impacts but accumulates oxygen due to adsorption processes. The angular distribution of reflected particles is highly dependent on the surface structure and the angle of incidence, with a higher ratio of specular reflection observed on smoother surfaces and at larger incidence angles. This is confirmed by the few experimental results available. We further present first results of the impingement of AO on SiO2 surfaces obtained with the same method. Here we study especially the influence of different interactions. The talk is completed with an outlook on the role of specific interactions in general.

Keywords: atomic oxygen impact; molecular dynamics simulations; very low earth orbit satellites; alumina; silica