INVESTIGADORES
VALENTINUZZI Maria Cecilia
congresos y reuniones científicas
Título:
Oxidation state detrmination by RRS with an energy dispersive system
Autor/es:
HÉCTOR JORGE SÁNCHEZ; MARÍA CECILIA VALENTINUZZI; JUAN JOSÉ LEANI
Lugar:
Río de Janeiro
Reunión:
Congreso; XI Latin American Seminar of Analysis by X Ray Techniques; 2008
Resumen:
In
this work we present preliminary results regarding the possibility of
determining the oxidation state by resonant Raman scattering using an energy
dispersive system.
Several
measurements of samples of Cu, CuO and Cu3O were carried out using synchrotron
radiation at the XRF beamline of the LNLS (Campinas, Brazil). The samples were
irradiated with monochromatic photons having energy close but lower than the
absorption edge of cooper. In addition,
fluorescence-EXAFS spectra were taken by high-resolution energy scannings
around the absorption edge of cooper.
The
RRS peaks were analyzed with specific programs for fitting the experimental
data to theoretical expressions. After that, residuals were determined in the
low energy side of the RRS peaks. These residuals were treated with FFT
smoothing methods taking into account the instrument functions of the detecting
system. The results show an oscillation pattern that depends on the sample,
i.e. on the oxidation state of cooper.
The
EXAFS spectra were treated with normal procedures and oscillations were
isolated.
The
results show that the oxidation state can be clearly discriminated by the RRS
analysis. Moreover, a significant (and, somehow, surprising) similarity can be
appreciated with the EXAFS patterns of the corresponding samples. More
measurements in different samples will be carried out in order to verify the
present results and, hopefully, to establish a repetitive and reliable method
of structural determination.