Design of an electron spectrometer for automated photoelectron diffractogram imaging over π steradians

• Published in: Journal of electron spectroscopy and related phenomena 1997-01, Vol.83 (1), p.99-112
• Main Authors: Patthey, L., Bullock, E.L.
• Format: Article
• Language: English
• Subjects: Diffractograms; Electron spectrometer; Interdiffusion
• ISSN: 0368-2048; 1873-2526
• DOI: 10.1016/S0368-2048(96)03061-7

An electron spectrometer is presented which has been designed and built for the fast automated acquisition of photoelectron diffraction data over π steradians above single crystal surfaces. The principle features include the use of externally-selectable stainless steel channel arrays in front of the electron optics for high accuracy definition of the analyzer acceptance angle, a five channeltron detection system allowing the determination of the photocurrent from a given photoemission core level or Auger transition without changing the analyzer energy, a sample holder with heating and cooling capabilities which has been designed for very high (< 0.1°) angular control around both the polar and azimuthal rotation axes, and an automated data acquisition system to perform the angular scanning, collect the data, and represent it in the form of photoelectron ‘diffractograms’. These data provide a chemically specific visualization of interatomic directions in the first few atomic layers of the system of interest and can be used to image intra-molecular bonds of molecules deposited on surfaces, follow the epitaxial growth of one substance on the ordered surface of another, or study interdiffusion at interfaces.