Ultraviolet-photoemission and electron-energy-loss spectroscopic studies ofTc99

Angle-integrated ultraviolet-photoemission and reflection electron-energy-loss spectra have been obtained for ${}_{}{}^{99}{}_{}{}^{}\mathrm{Tc}$ for the first time. The photoemission energy distribution curves are in semiquantitative agreement with the calculated density of states. The work function of this material was found to be 5.0±0.5 eV. The volume and surface plasmons are at 25.0±0.5 and 20.7±0.5 eV, respectively. A lower plasma oscillation is observed at 9.5±0.5 eV. $N_{\mathrm{I}}$ and $N_{\mathrm{II},\mathrm{III}}$ ionization energies obtained are in good agreement with x-ray measurements. Comparisons of ${}_{}{}^{99}{}_{}{}^{}\mathrm{Tc}$ properties to those of other transition metals in period 5 are also given.