Whereas the objective lens used to be the most important aspect in terms of resolution and tilt capabilities, this requirement no longer plays a significant role in corrected systems. Since a corrector allows a system to obtain directly interpretable resolution down to the information limit of the total microscope system [2], the value for information limit on the basic system becomes the resolution-limiting specification in imaging, and therefore a key specification. For enhanced probe and analysis performance, total stability of the complete system, both electronically and mechanically, will determine the ultimately possible performance.

The ‘TITAN’ new (S)TEM corrector platform is a revolutionary new design. The reason this is needed is described above; existing columns couldn’t handle correctors properly, and implementing correctors into older column designes give rise to problems with installation and ultimately, problems realizing a distinct benefit of the corrector. Titan is a completely new column with much improved stabilities in mechanical, electrical and thermal behaviour. This allows sub-angstrom results to be obtained easily in imaging as well as probe modes. Combined with a monochromator allowing energy resolutions of 0.2eV to be reached, similar work can be done on these systems when compared to a synchrotron, however the spatial resolution is better in a Titan. However the synchrotron can get through thicker samples... Band-gap studies at high resolution are one of the key areas also currently being exploited. Other areas of interest are sub-Angstrom microanalysis and imaging of catalyst particles without the delocalization problem. Some recent results obtained with this system will be presented.

References
[1] M. Haider, G. Braunhausen, and E. Schwan, Optik 99 (1995) 167.
[2] B. Freitag et al., Ultramicroscopy 102 (2005) 209.
[3] P.C. Tiemeijer, Inst. Phys. Conf. Ser. 161 (1999) 191.
*Current address: 3075 Asbury Dr., Columbus, Ohio 43221-2671.