Channeling Vibrational Energy To Probe the Electronic Density of States in Metal Clusters

Abstract

We investigate the electronic density of states (DOS) of isolated neutral cobalt clusters by probing the temperature-modulated population of electronic states through UV photoionization. The temperature is controlled via resonant excitation of lattice vibrations using the free-electron laser FELICE, after which the vibrational and electronic systems equilibrate through the electron-phonon coupling, redistributing the population of electronic states. The data are analyzed by surface photoemission theory, modified to incorporate the realistic DOS.

The repopulation of electronic states upon vibrational excitation of niobium carbide clusters

“…C.DFT-based electronic repopulation. In our final model we use the information about the Kohn-Sham orbitals for a cluster obtained from the DFT calculations in combination with the Fermi-Dirac distribution to determine the population of the electronic density of states, as successfully applied for metallic clusters 16 . Inspired by a model of two displaced harmonic oscillators 35,36 , we further assume that transitions from each populated electronic level E i can be simulated by a Gaussian function dubbed transition band.…”

“…The reverse experiment, where the cluster nuclear coordinates are excited in the electronic ground state and the energy is transferred to electronically excited states, which can eventually lead to ionization, was primarily used to study the vibrational properties of clusters 14,15 . Recently, we presented a study demonstrating the possibility to probe the population redistribution over lowlying electronic levels using UV photoionization 16 .…”

Direct IR Spectroscopic Detection of a Low‐Lying Electronic State in a Metal Carbide Cluster

“…In a recent work, we have studied how the excitation of pure vibrational coordinates can be followed by a relaxation into electronically excited states through vibronic coupling. This way, low‐lying electronic states are revealed by the appearance of extra structure in the photoionization spectrum ,. The electronic states had energies of approx.…”

Orbit and spin resolved magnetic properties of size selected [ConRh]+ and [ConAu]+ nanoalloy clusters

“…Starting points for these calculations were the non spin-orbital coupled density function theory (DFT) 34,35 calculations that we have performed earlier for a range of cobalt clusters 28 and which are compared with their experimentally obtained vibrational spectra in order to confirm their ground state geometry. Starting points for these calculations were the non spin-orbital coupled density function theory (DFT) 34,35 calculations that we have performed earlier for a range of cobalt clusters 28 and which are compared with their experimentally obtained vibrational spectra in order to confirm their ground state geometry.…”

“…Geometry of the Co 13 cluster as calculated in our group by Jalink et al28 (left and middle) compared with Co 12 Rh as calculated by Aguilera-Granja et al 21 (right). Paper PCCP Published on 19 June 2015.…”