Threshold ionization energies of Au2+, Au3+, and Au4+

Abstract Threshold ionization energies (IE) for the metal ions Au 2+ , Au 3+ , and Au 4+ have been determined experimentally by utilizing a sequential ionization process. No experimental IE values are available in the literature for charge states of Au higher than Au 2+ . The experimental IE value for Au 3+ is higher by 4 eV and that for Au 4+ is in good agreement (within 0.6 eV) with Lisitzin's [1] calculated values. However, the present experimental IE values for Au 3+ and Au 4+ are found to be lower than the values calculated by Carlson et al- [2]. The Au 3+ value calculated by the extrapolation method is within 2.6 eV of the experimental Au 3+ IE value.