Mössbauer Spectroscopy: A Method for Nanomaterials Characterization

The corrosion product films formed on industrial Fe-C steel with a low carbon concentration, after immersion in the diluted ammoniac solutions (NH3 solu-tions, ammonium salts solutions), have been investigated by means of 57Fe Mössbauer spectroscopy. The amorphous Fe3+ oxyhydroxides are the major constituent of the cor-rosion layers. An inhibition of corrosion was found to occur in the ammoniac solutions. The NO3- anion in a solution of 0.1 M NH4Cl has an inhibiting effect. The inhibition ef-fect of one compound: N-ciclohexil-benzothiazole-sulphenamida (NCBSA) on the cor-rosion of carbon-steel in diluted ammonia solution was studied. All surface spectra show that there is a magnetic anisotropy on the surface of the samples.