Description:
<jats:title>Abstract</jats:title><jats:p>The surface segregational processes taking place during the activation of the hydrogen storage material TiFe were studied by Auger electron spectroscopy (AES). <jats:italic>In situ</jats:italic> treatment of TiFe with 2 × 10<jats:sup>−5</jats:sup> mbar hydrogen at 870 K results in the formation of an overlayer, with Ti as the only metallic component. To understand the catalytic mechanism of the hydrogen uptake it is of major importance to gain knowledge about the chemical state of this Ti overlayer. Recent work demonstrates that, in the case of Ti, it is possible to identify not only titanium oxides but also titanium hydrides by line‐shape effects, which act on the Ti L<jats:sub>3</jats:sub>M<jats:sub>23</jats:sub>V Auger signal. By comparison with Ti reference spectra measured before and after gas exposure, it becomes clear that the overlayer consists of titanium hydride. In order to emphasize the line‐shape effects, deconvolved spectra are shown. Since Fe was not detectable on the surface of the material after hydrogen treatment, it is concluded that the titanium hydride must catalyse the hydrogen uptake of activated TiFe.</jats:p>