Surface Characterization of NbO Islands Formed on Nb(100) by X-Ray Photoelectron Diffraction

• Published in: Topics in catalysis Vol. 61; no. 9-11; pp. 784 - 791
• Main Authors: Pancotti, A., Wang, J., Rezende, A. C. S. A., Santos, D. P., de Siervo, A., Landers, R., Nascente, P. A. P.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-06-2018; Springer Nature B.V
• Subjects: Catalysis; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Diffraction; Electrons; High vacuum; Industrial Chemistry/Chemical Engineering; Low energy electron diffraction; Niobium oxides; Original Paper; Pharmacy; Physical Chemistry; Single crystals; Surface properties; Surface structure; Synchrotron radiation; X ray photoelectron spectroscopy; X-ray diffraction; X-ray photoelectron diffraction; Surface reconstruction; Niobium oxide; Niobium
• ISSN: 1022-5528; 1572-9028
• DOI: 10.1007/s11244-018-0946-x

An ordered thin film of niobium oxide (NbO) was formed on the Nb(100) surface by heating the niobium single crystal at 1023 K for 2 min under an oxygen atmosphere. The surface composition was analyzed by X-ray photoelectron spectroscopy (XPS), and the surface structure was characterized by low energy electron diffraction (LEED) and X-ray photoelectron diffraction (XPD) generated by synchrotron radiation. Annealing at 1223 K in ultra-high vacuum yielded a reconstructed (3 × 1) LEED pattern. XPS measurements indicated that the surface comprised of metallic and oxidized niobium species. The comparison between experimental and theoretical XPD results indicated that 60% of the Nb(100) surface was covered by two-layered nanoislands of NbO, and 40% had bare patches.