INVESTIGADORES
TRINCAVELLI Jorge Carlos
congresos y reuniones científicas
Título:
Extension of the peak-to-background quantification to light element analysis Comparison with other standardless methods
Autor/es:
JÁNOS OSÁN; GUSTAVO CASTELLANO; JORGE TRINCAVELLI; SZABINA TÖRÖK
Lugar:
Cádiz, España
Reunión:
Congreso; 8th European Workshop on Modern Developments and Applications in Microbeam Analysis; 2003
Institución organizadora:
European Microbeam Analysis Society
Resumen:
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The standardless peak-to-background (P/B) method
is a simple and powerful utility for quantitative electron probe microanalysis of
bulk samples and large (d > 1 mm) particles. The method yields very
satisfactory results, when the concentration of oxygen is usually calculated from
stoichiometry. At present, the majority of the energy dispersive detectors is
equipped with a thin window allowing the detection of low-Z elements such as B, C and O. A lot of applications demand the quantitative
determination of light elements, because the stoichiometric information is
insufficient when B and C are present in the sample.
In order to solve this analytical problem, the
peak-to-background method implemented in the MULTI software has been extended
to deal with light-element X-ray intensities and low-energy bremsstrahlung background.
The mass absorption coefficients of Henke and Ebisu have been incorporated into
the software. As the empirical mathematical formulae existing for prediction of
the bremstrahlung background did not describe well the low-energy part, a recently
developed modified formula is used. Special attention was paid on the
evaluation of X-ray spectra, since the accurate determination of the background
intensities is essential for the P/B method.
The
method was tested on bulk and particulate (d
> 1 mm) standards
containing light elements. The analytical performance was compared with
commercial (first principles and fitted standards) standardless methods and a
reverse Monte Carlo method. The results show
that the semi-quantitative analysis of bulk samples and relatively large
particles (d > 1 mm) is
feasible with the extended P/B method, including light elements. For particle
analysis, the present method is superior to the tested commercial methods. The reverse
Monte Carlo method provides more accurate
results, but it is more time-consuming due to the complexity of the
calculations.
