Chemical environment determination of iron oxides using RRS spectroscopy

JUAN JOSÉ LEANI; HÉCTOR SÁNCHEZ; MARÍA VALENTINUZZI; C.A. PEREZ

X-RAY SPECTROMETRY

JOHN WILEY & SONS LTD

Año: 2011 vol. 40 p. 15 - 18

0049-8246

This article presents first results of determination of the oxidation state of several Fe samples by means of resonant Ramanscattering spectroscopy (RRS) using monochromatic synchrotron radiation with an energy-dispersive system. Measurementsof samples of Fe, FeO, Fe2O3 and Fe3O4 were carried out at the XRF station of the D09B-XRF beamline at Brazilian synchrotronfacility (LNLS, Campinas, Brazil). The sampleswere irradiated with monochromatic photons having energy close and lower thanthe K absorption edge of iron in order to inspect the RRS emissions. The RRS spectra were analyzed with specific programs forfitting the experimental data to theoretical expressions. Then, residuals were determined in the low-energy side of the RRSpeaks. These residuals were treated with Fast Fourier Transform (FFT) smoothing methods taking into account the instrumentfunctions of the detecting system. The residuals show an oscillation pattern that depends on the studied sample, i.e. on theoxidation state of Fe. The changes existing in the RRS structure between Fe and its oxides are clearly discriminated, suggestingchemical environment characterization by RRS spectroscopy using an energy-dispersive system combined with synchrotronradiation. Copyright
c 2011 John Wiley & Sons, Ltd.