The rusts formed on mild steel (15-year exposure) and weathering steel (32-year exposure) exposed to an industrial environment have been characterized by means of X-ray diffraction technique and 57 Fe Mössbauer spectroscopy. By using an X-ray diffraction method, it is suggested that the rusts formed on both steels consist of the crystalline α-FeOOH, γ -FeOOH and an X-ray amorphous phase, which gives no peak to X-ray diffraction pattern. The amount of the X-ray amorphous phase exceeds 50% of the total amount of the rust. The 57 Fe Mössbauer spectra observed at 10 K indicate that the rust contains only α-FeOOH, γ -FeOOH and Fe 3−δ O 4 (γ -Fe 2 O 3 ) for mild steel, and only α-FeOOH and γ -FeOOH for weathering steel. The X-ray amorphous substance in the rust layer formed on mild steel possesses the structures of mainly α-FeOOH showing superparamagnetism owing to its small particle size, and Fe 3−δ O 4 (γ -Fe 2 O 3 ). They are contained both in the inner rust layer and in the outer rust layer. The X-ray amorphous phase in the rust layer formed on weathering steel is mainly α-FeOOH.

No abstract

No abstract

We have carried out Mössbauer spectroscopy and nuclear resonant inelastic scattering to elucidate the lattice dynamics in filled-Skutterudite compounds, especially phosphides. The second-order Doppler shift obeys the Debye model in RFe 4 P 12 . Nuclear quadrupole interaction reveals an unusual temperature dependence in these compounds. An anomaly is observed in 57 Fe nuclear resonant inelastic scattering of these compounds. The energy where the anomaly observed in SmFe 4 P 12 agrees with the phonon excitation energy observed by 149 Sm nuclear resonant inelastic scattering. We have also performed the 99 Ru Mössbauer measurements of SmRu 4 P 12 .

No abstract