Atomic quadrupolar photoemission asymmetry parameters from a solid state measurement

Area of Science:

• Atomic and Molecular Physics
• Surface Science
• X-ray Spectroscopy

Background:

• Core-level photoemission is sensitive to electron and photon interactions.
• Dipole-quadrupole interference influences photoemission asymmetry.
• Measuring this interference is crucial for understanding electronic structure.

Purpose of the Study:

• To propose a novel method for measuring the asymmetry parameter gamma.
• To utilize condensed thin films for enhanced measurement sensitivity.
• To investigate dipole-quadrupole interference in core-level photoemission.

Main Methods:

• Employing condensed thin films for X-ray standing wave field absorption.
• Monitoring photoemission to detect asymmetry.
• Applying the method to C, O, and F 1s photoemission at ~3 keV photon energies.

Main Results:

• Successfully measured the asymmetry parameter gamma in C, O, and F 1s photoemission.
• Demonstrated the advantages of condensed thin films over gas-phase measurements.
• Showed that the combined nondipole asymmetry factor (delta+gamma/3) for non-s states can be determined.

Conclusions:

• The proposed method provides an effective way to measure dipole-quadrupole interference.
• Condensed thin films offer a practical and advantageous approach for such measurements.
• This technique advances the study of electron and photon interactions in materials.