Compositional and structural characterization of nanoporous films produced by iron anodizing in ethylene glycol solution

• Published in: Applied surface science Vol. 257; no. 9; pp. 3893 - 3897
• Main Authors: Jagminas, Arūnas, Mažeika, Kęstutis, Bernotas, Nerijus, Klimas, Vaclovas, Selskis, Algirdas, Baltrūnas, Dalis
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.02.2011; Elsevier
• Subjects: Anodizing; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Electrolytes; Ethylene glycol; Exact sciences and technology; Iron; Iron oxides; Mössbauer spectroscopy; Nanocomposites; Nanomaterials; Nanostructure; Nanostructures; Physics; Spectra; Nanostructures; Iron oxides; Anodizing; Mössbauer spectroscopy; Iron oxide; Transition elements; Moessbauer spectroscopy; Iron
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2010.11.113

[Display omitted] ▶ The anodizing of iron in ethylene glycol containing NH4F and H2O has been optimized. ▶ In this electrolyte, nanoporous films up to 10μm thick can be formed. ▶ Mössbauer spectra evidenced these films consisting of lepidocrocite (γ-FeOOH) and some Fe(II) compounds. We report on the composition and morphology of as-grown anodic oxide films onto the iron surface in an ethylene glycol solution containing some NH4F and H2O by anodizing under direct current bias. Decrease in the content of NH4F and the temperature of electrolyte allow us to form either nanochannel or nanotubular films over a larger potential window, ca. from 30 to 100V. By this way, the films in thickness of up to10μm have been formed. Mössbauer spectra recorded at room to cryogenic temperatures under conversion electron and transmission modes revealed the formation of lepidocrocite (γ-FeOOH) film containing some Fe(OH)2 and/or FeF2·4H2O. An increase in anodizing voltage results in fabrication of more porous and less Fe(II) compounds containing films.