STM study of surface restructuring of oxidized Cu(100)

• Published in: Surface science 2024-02, Vol.740, p.122403, Article 122403
• Main Authors: Shields, Seth S., Gupta, Jay. A.
• Format: Article
• Language: English
• Subjects: copper oxidation; reconstruction; scanning tunneling microscopy; STM; surface
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/j.susc.2023.122403

•Scanning tunneling microscopy study of the Cu(100) missing row reconstruction•The missing row reconstruction is robust•Vacuum annealing of the oxidized Cu(100) surface led to Cu(110) facets•The Cu(110) facets are covered with a known oxygen reconstruction The Cu(100) surface offers a model platform for the investigation of the copper oxidation process. Starting from clean Cu(100), we characterized oxidized surfaces with varying oxygen exposure, sample temperature, and post-oxidation annealing conditions. Scanning tunneling microscopy was used to characterize the surfaces with atomic resolution imaging at 78 K. Annealing in O2 (P∼ 5·10−6 mbar) at 80-260°C led to the (2√2 x √2) R45°Cu(100)-O missing row reconstruction (MRR), which self-limited at monolayer coverage and was relatively insensitive to exposure or temperature in this range. Further annealing of the MRR surface in UHV (PO2< 10−9 mbar) at 160°C resulted in large scale reorganization of the surface into MRR areas with a higher degree of step-bunching, coexisting with facet-like hills. The facets are decorated by terraces with a quasi-hexagonal lattice that we attribute to a Cu(110) c(6×2) oxygen induced reconstruction. [Display omitted]