Open AccessSurface optical reflectance combined with x-ray techniques during gas-surface interactions
Author(s) -
Stefano Albertin,
Johan Gustafson,
Jianfeng Zhou,
Sebastian Pfaff,
Mikhail Shipilin,
Sara Blomberg,
Lindsay R. Merte,
Olof Gutowski,
Ann Christin Dippel,
Johan Zetterberg,
Edvin Lundgren,
Uta Hejral
Publication year - 2020
Publication title -
journal of physics. d, applied physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.857
H-Index - 198
eISSN - 1361-6463
pISSN - 0022-3727
DOI - 10.1088/1361-6463/ab77df
Subject(s) - x ray reflectivity , oxide , materials science , analytical chemistry (journal) , reflectivity , diffraction , in situ , x ray , phase (matter) , morphology (biology) , optics , thin film , chemistry , nanotechnology , physics , geology , metallurgy , paleontology , organic chemistry , chromatography
High energy surface x-ray diffraction (HESXRD), x-ray reflectivity (XRR), mass spectrometry (MS) and surface optical reflectance (SOR) have been combined to simultaneously obtain sub-second information on the surface structure and morphology from a Pd(100) model catalyst during in situ oxidation at elevated temperatures and pressures resulting in Pd bulk oxide formation. The results show a strong correlation between the HESXRD and SOR signal intensities during the experiment, enabling phase determination and a time-resolved thickness estimation of the oxide by HESXRD, complemented by XRR measurements. The experiments show a remarkable sensitivity of the SOR to changes in the surface phase and morphology, in particular to the initial stages of oxidation/reduction. The data imply that SOR can detect the formation of an ultrathin PdO surface oxide layer of only 2–3 Å thickness.