Search

Inner-shell photoionization spectra of Hg n clusters ( n ⩽8) have been obtained with a molecular beam experiment using synchrotron radiation from the VUV storage ring at Orsay. The photoionization spectra exhibit two strong autoionization resonances which are red-shifted with increasing cluster size. The present results are compared with solid-state experimental data which indicate that the clusters (⩽Hg 8 ) do not yet have metallic character.

We report the first observation of the high vibronic levels of the ${\mathrm{Na}}_{3}$ ground state, performed by stimulated emission spectroscopy. The highest cross sections of the process, which uses the ${C}^{2}$E'' state as an intermediate state, are obtained for combinations of symmetric stretch and bending modes. These experimental results are of primary importance for the understanding of energy-level structures in systems exhibiting strong vibronic coupling.

One-photon ionization experiments were performed on K 2 and Na 3 in supersonic molecular beams using a frequency-doubled dye laser and a mass spectrometric detection system. Wavelength scans across the ionization potential of K 2 clearly indicate autoionizing Rydberg levels of low n -values and ungerade symmetry dominating the direct photoionization processes. The ionization of Na 3 , on the other hand, does not exhibit an expressed structure of autoionizing Rydberg states. Possible explanations are discussed.

Inner-shell autoionization spectra obtained with synchrotron radiation are reported for mercury clusters ${\mathrm{Hg}}_{n}$, $n\ensuremath{\le}40$. For the small clusters $n\ensuremath{\le}12$ the spectral behavior as a function of size is interpreted in terms of an excitonic model. For larger cluster sizes a gradual deviation from van der Waals bonding is observed. The asymmetry occuring in the line profiles reflects the progressive construction of the $\mathrm{sp}$ conduction band.