A comparative study of the direct laser nitridation of Ti and Ta metals has been carried out “in situ” by XPS. Metal foils have been subjected to laser irradiation in the prechamber of the spectrometer under different conditions and gas atmospheres (vacuum, N2, N2+H2, N2+O2, NH3). XPS spectra of the Ti2p, Ta4f, O1s and N1s photoemission levels have been thoroughly studied both by fitting analysis and quantitative evaluation of the different fitting bands. Other characterization analysis by scanning electron microscopy have complemented this study. Significant differences in chemical states and distribution of Mn+ species (M: Ti and Ta) and content and chemical state of incorporated nitrogen have been found depending of the gases used for the treatments, the type of metal and the laser irradiation conditions. These differences in chemical state are accompanied by changes in the surface topography, in-depth distribution of nitrogen within the samples and long term stability of the surface nitridized samples. A laser interaction model that includes sublimation and surface reactions processes of ablated species has been proposed to account for these results.
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