Practical Electron Microscopy and Database

In order to optimize the acquisition of holograms, in many cases, the microscopes need to be re-configured. For instance, Cooper et al. [1] turned off the probe corrector in their FEG FEI Titan microscope even though it had been installed. Both the objective lens and third condenser lens were turned off, and a Lorentz lens was used in order to extend the holographic field of view to 1500 x 700 nm².

On the other hand, Lorentz mode can be obtained in conventional TEM systems by turning off the normal objective lens and focusing the object with an objective minilens below the lower polepiece of the normal objective lens. For instance, Zheng et al. [2] used this Lorentz mode to get large area phase mappings of the electron holograms.

[1] David Cooper, Pierrette Rivallin, Jean-Michel Hartmann, Amal Chabli, and Rafal E. Dunin-Borkowski, Extending the detection limit of dopants for focused ion beam prepared semiconductor specimens examined by off-axis electron holography, JOURNAL OF APPLIED PHYSICS 106, 064506 (2009).
[2] C. L. Zheng, K. Scheerschmidt, H. Kirmse, I. Häusler, W. Neumann, Imaging of three-dimensional (Si,Ge) nanostructures by off-axis electron holography, Ultramicroscopy 124 (2013) 108–116.