Moessbauer-effect studies of crystalline and amorphous iron-based alloys and of corrosion processes at iron surfaces

Technical Report · Fri Jan 01 04:00:00 EST 1982

OSTI ID:6619957

Lin, M C

Moessbauer effect spectroscopy was used to measure the temperature dependence of the /sup 57/Fe effective magnetic hyperfine field H/sub eff/ and isomer shift delta of Fe/sub 3/Al/sub x/Si/sub 1-x/ (0 less than or equal to x less than or equal to 1) from 77K to the Curie temperature. The observed dependence of H/sub eff/ and delta on Al concentration can be qualitatively understood in terms of the calculated band structure of Fe/sub 3/Si. /sup 57/Fe Moessbauer spectra was also obtained at liquid nitrogen and room temperatures for metallic glasses Fe/sup 82/B/sub 18-x/Be/sub x/ with 0 less than or equal to x less than or equal to 6. Width of the probability distribution function of the effective magnetic hyperfine field remains constant at 80 k0e. However, the effective magnetic hyperfine field at 77/sup 0/K initially increases with Be content, but starts to decrease as x exceeds four. The isomer shift is -0.032 mm/s for samples with x less than or equal to 4 but changes to -0.050 mm/s for samples with x > 4. The crystallization products obtained upon annealing the samples were identified. Moessbauer spectroscopy and electrochemical measurements were used to study effects of chloride ions on a passivated iron surface in boric acid-sodium borate buffer solution at pH 8.4. The Moessbauer spectrum of the oxide film formed after breakdown of the passive film by aggressive chloride ions consists of a doublet with linewidth of 0.51 +- 0.03 mm/s, isomer shift of 0.35 +- 0.02 mm/s relative to the metallic iron, and quadrupole splitting of 0.79 +- 0.01 mm/s. The quadrupole splitting differs from that of the passive film which has line-widths of 0.55 +- 0.08 mm/s, an isomer shift of 0.36 +- 0.01 mm/s, and a quadrupole splitting of 0.94 +- 0.06 mm/s.

• Research Organization: Ames Lab., IA (USA)
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 6619957
• Report Number(s): IS-T-993; ON: DE83004980
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
360105 -- Metals & Alloys-- Corrosion & Erosion
ALLOYS
ALUMINIUM ALLOYS
AQUEOUS SOLUTIONS
BERYLLIUM ALLOYS
BORON ALLOYS
CHLORIDES
CHLORINE COMPOUNDS
DISPERSIONS
ELEMENTS
EVEN-ODD NUCLEI
HALIDES
HALOGEN COMPOUNDS
HYPERFINE STRUCTURE
INTERMEDIATE MASS NUCLEI
IRON
IRON 57
IRON ALLOYS
IRON BASE ALLOYS
IRON ISOTOPES
ISOMER SHIFT
ISOTOPES
LOW TEMPERATURE
MAGNETIC FIELDS
MEDIUM TEMPERATURE
METALS
MIXTURES
MOESSBAUER EFFECT
NUCLEI
PASSIVATION
SILICON ALLOYS
SOLUTIONS
STABLE ISOTOPES
TEMPERATURE DEPENDENCE
TRANSITION ELEMENTS