Interatomic Coulombic decay in mixed NeKr clusters.

Area of Science:

• Atomic and Molecular Physics
• Quantum Chemistry
• Surface Science

Background:

• Interatomic Coulombic decay (ICD) is a phenomenon where an excited atom in a molecule or cluster transfers its energy to a neighboring atom, leading to the emission of an electron.
• Understanding ICD in mixed atomic systems is crucial for characterizing energy transfer dynamics and electronic interactions in van der Waals clusters.

Purpose of the Study:

• To investigate the occurrence and characteristics of interatomic Coulombic decay (ICD) in mixed Neon-Krypton (NeKr) clusters.
• To explore the influence of photon energy, cluster composition, and cluster size on the ICD process in NeKr systems.

Main Methods:

• Photoelectron spectroscopy was employed to detect electrons emitted during the ICD process.
• Coincidence measurements were performed with Ne 2s photoelectrons to identify and analyze the ICD signal.
• Systematic variation of experimental parameters including photon energy, Kr concentration, and cluster size.

Main Results:

• A distinct ICD feature was observed in the kinetic energy spectrum of emitted electrons, ranging from 9 to 12 eV.
• The ICD process was initiated by a Ne 2s vacancy, filled by a Ne 2p electron, with subsequent electron emission from a Kr 4p level.
• The ICD electron energy showed a slight increase and the development of a shoulder with increasing Kr concentration (from 2% to 5%), suggesting surface versus bulk effects.

Conclusions:

• The study confirms the occurrence of ICD in mixed NeKr clusters, demonstrating efficient energy transfer between Neon and Krypton atoms.
• The observed dependence of ICD electron energy on cluster composition provides insights into the role of atomic environment and cluster structure.
• The findings contribute to a deeper understanding of fundamental electronic processes in mixed atomic systems and van der Waals interactions.