Quantitative Phase Retrieval in Transmission Electron Microscopy

• Author / Creator

  McLeod, Robert A.

• Phase retrieval in the transmission electron microscope offers the unique potential to collect quantitative data regarding the electric and magnetic properties of materials at the nanoscale. Substantial progress in the field of quantitative phase imaging was made by improvements to the technique of off-axis electron holography. In this thesis, several breakthroughs have been achieved that improve the quantitative analysis of phase retrieval. An accurate means of measuring the electron wavefront coherence in two-dimensions was developed and pratical applications demonstrated. The detector modulation-transfer function (MTF) was assessed by slanted-edge, noise, and the novel holographic techniques. It was shown the traditional slanted-edge technique underestimates the MTF. In addition, progress was made in dark and gain reference normalization of images, and it was shown that incomplete read-out is a concern for slow-scan CCD detectors. Last, the phase error due to electron shot noise was reduced by the technique of summation of hologram series. The phase error, which limits the finest electric and magnetic phenomena which can be investigated, was reduced by over 900 % with no loss of spatial resolution. Quantitative agreement between the experimental root-mean-square phase error and the analytical prediction of phase error was achieved.

• Subjects / Keywords

  • Phase error
  • Hologram Series
  • Reference Images
  • Transmission electron microscope (TEM)
  • Phase resolution
  • Gaussian random-walk
  • Incomplete Read-out
  • Detector Quantum Efficiency (DQE)
  • Noise-transfer Function (NTF)
  • Complex Circular Random Variables (CCRV)
  • Quantitative Electron Microscopy
  • Electron coherence
  • Off-axis Electron holography
  • Modulation-transfer Function (MTF)
  • Holographic Visibility
  • Coherence loss by inelastic scattering

• Graduation date

  Fall 2013

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/R35X25N02

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.