Ionization potentials of metal clusters studied with a broad range, tunable vacuum ultraviolet light source

Area of Science:

• Physical Chemistry
• Atomic and Molecular Physics
• Materials Science

Background:

• Accurate measurement of ionization potentials is crucial for understanding metal cluster properties.
• Traditional methods often require complex and expensive equipment like laser setups or synchrotron light sources.

Purpose of the Study:

• To develop and present a more accessible experimental setup for determining metal cluster ionization potentials.
• To measure the adiabatic ionization potentials (AIPs) of tin clusters (Snₙ, n=8-12) using the novel method.

Main Methods:

• Utilized a commercial Xenon (Xe) flash lamp coupled with a vacuum monochromator.
• Acquired photoionization efficiency curves to extract adiabatic ionization potentials (AIPs).
• Employed Franck-Condon simulations to interpret experimental photo-ion yield data.

Main Results:

• Determined the AIPs for Sn₈ to Sn₁₂ clusters, with values ranging from 6.34 to 6.93 eV.
• Identified specific AIPs for different isomers of Sn₁₂ clusters (IsoI and IsoIII).
• Quantified the uncertainty in AIP measurements, primarily attributed to monochromator bandwidth.

Conclusions:

• The Xe flash lamp and monochromator setup offers a viable alternative for measuring metal cluster ionization potentials.
• The study provides new experimental data for tin cluster AIPs, contributing to the understanding of their electronic structure.
• The influence of isomers on photo-ion yield was analyzed and compared with existing literature data.