| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1677858 | Ultramicroscopy | 2011 | 8 Pages |
We discuss a new interpretation of mirror electron microscopy (MEM) images, whereby electric field distortions caused by surface topography and/or potential variations are sufficiently large to create caustics in the image contrast. Using a ray-based trajectory method, we consider how a family of rays overlaps to create caustics in the vicinity of the imaging plane of the magnetic objective lens. Such image caustics contain useful information on the surface topography and/or potential, and can be directly related to surface features. Specifically we show how a through-focus series of MEM images can be used to extract the contact angle of a Ga droplet on a GaAs (001) surface.
Research highlights► We discuss a new interpretation of mirror electron microscopy (MEM) images. ► Mirror microscopy images often contain strong caustic features. ► A family of ray-based electron trajectories overlaps to create caustics. ► Image caustics contain useful information on the surface topography and potential. ► We extract the contact angle of a Ga droplet on a GaAs (001) surface.
