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Title: Ultrahigh-spatial-resolution chemical and magnetic imaging by laser-based photoemission electron microscopy

We report the first experiments carried out on a new chemical and magnetic imaging system, which combines the high spatial resolution of a photoemission electron microscope (PEEM) with a continuous-wave deep-ultraviolet laser. Threshold photoemission is sensitive to the chemical and magnetic structures of the surface of materials. The spatial resolution of PEEM is limited by space charging when using pulsed photon sources as well as aberrations in the electron optics. We show that the use of a continuous-wave laser enabled us to overcome such a limit by suppressing the space-charge effect, allowing us to obtain a resolution of approximately 2.6 nm. With this system, we demonstrated the imaging of surface reconstruction domains on Si(001) by linear dichroism with normal incidence of the laser beam. We also succeeded in magnetic imaging of thin films with the use of magnetic circular dichroism near the Fermi level. The unique features of the ultraviolet laser will give us fast switching of the incident angles and polarizations of the photon source, which will be useful for the characterization of antiferromagnetic materials as well as ferromagnetic materials.
Authors:
; ;  [1] ;  [2]
  1. The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581 (Japan)
  2. (Japan)
Publication Date:
OSTI Identifier:
22392366
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 86; Journal Issue: 2; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; ANTIFERROMAGNETIC MATERIALS; ELECTRON MICROSCOPES; ELECTRON MICROSCOPY; EMISSION SPECTROSCOPY; FERMI LEVEL; FERROMAGNETIC MATERIALS; LASERS; MAGNETIC CIRCULAR DICHROISM; PHOTOELECTRON SPECTROSCOPY; PHOTOEMISSION; POLARIZATION; SPACE CHARGE; SPATIAL RESOLUTION; THIN FILMS; ULTRAVIOLET RADIATION