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Q42: 2D Materials: Advanced Characterization IV

Room 318

Sponsoring Units: DMPChair: Christopher Smallwood, San Jose State UniversitySession Type:
  • Focus

Wed. March 8, 4:36 p.m. – 4:48 p.m. PST

Room 318

High quality ARPES measurements, particularly micro/nanoARPES, require highly optimized alignment of the excitation photon beam, sample, and analyzer focal point. Scienta Omicon's new DFS30 spectrometer (patent pending) simplifies this alignment by employing electronic adjustment of the analyzer focal point.  In this presentation we will show the first results from our ground-breaking real-time and in-situ Electrostatic 3D Focus Adjustment technology.  By replacing imprecise mechanical movements with precise electrostatic adjustments of the lens tables users are able to greatly improve data quality and repeatability in ARPES measurements, as well as providing significantly improved workflow, speed, and reproducibility when optimizing experimental conditions.

    Generally ARPES measurements require time consuming, iterative alignment of sample position and light source to match the photoelectron emission spot with the analyzer focal point.  Without optimized alignment operation of the analyzer measurement data quality may be compromised.  The Electrostatic 3D Focus adjustment technology allows users to generate dynamic lens tables in real time in order to achieve fully optimized deflection, angular and/or transmission modes for data collection. These live lens tables enable calibrated and continuous electronic shifting of the analyzer focal point in three dimensions.  This technology represents a major advancement for micro- and nano-ARPES.

    As part of our presentation, we will discuss how the alignment of focal point and emission spot is a general ARPES issue, but is particularly important for micro/nanoARPES application as misalignment effects scale with smaller spot sizes and photoelectron kinetic energy.  ARPES spectra of graphene measured at the Bloch beamline at MAX IV will be shown as a model case and used as an example to demonstrate the significant impact of the Electrostatic 3D Focus Adjustment on data quality.

 

Presented By

  • Timo Wätjen (Scienta Omicron)

Authors

  • Daniel A Beaton (Scienta Omicron Inc.)
  • Craig Polley (MAX IV Labratory)
  • Timo Wätjen (Scienta Omicron)
  • Marcus Lundwall (Scienta Omicron)
  • Khadiza Ali (MAX IV Labratory)
  • Patrik Karlsson (Scienta Omicron)