Compositional and structural depth profile analysis by confocal micro-XRF

PEREZ, R.D; SÁNCHEZ, H.J; SOSA, C.; PEREZ, C.A.; RUBIO, M.

Puebla

Seminario; XII Seminario Latinoamericano de análisis por técnicas de rayos x-SARX2010; 2010

The confocal setup consists of x-ray lenses in the excitation as well as in the detection channel. In this configuration, a micro volume defined by the overlap of the foci of both x-ray lenses is analyzed. Scanning this micro volume through the sample, 1-3 dimensional studies can be performed. For depth profiling studies, only the scan of the confocal volume in the normal direction to the sample is required. An elemental analysis is obtained by the detection of the x-ray fluorescence produced in the confocal volume. In addition, Energy Dispersive X-Ray Diffraction analysis (EDXRD) in the confocal volume can be performed using a continuous polychromatic source and an appropriated fixed geometry based on a low divergence optic. To implement the confocal setup, we used two monolithic semi-polycapillaries in the excitation and detection channel. The polycapillaries were made by means of drawing of multibundles of borosilicate glass capillaries in a heating furnace. The experiment was carried out at the D09B beamline of the Brazilian Synchrotron Light Laboratory (Laboratório Nacional de Luz Síncrotron, LNLS) using white beam. A silicon drift X-ray detector of 150 eV resolution at 5.9 keV was used for detection of scattered and characteristic photons. A mean spatial resolution of 90 micrometers for the three orthogonal axes was obtained. A detailed characterization of our confocal setup is described in this work. Elemental and structural x-ray microanalyses of stratified samples are shown.