Flexible formation of coherent probes on an aberration-corrected STEM with three condensers. Yi, F., Tiemeijer, P., & Voyles, P. M. Journal of Electron Microscopy, 59(S1):S15–S21, August, 2010. 00007
Flexible formation of coherent probes on an aberration-corrected STEM with three condensers [link]Paper  doi  abstract   bibtex   
We have used geometric optics calculations and experiments to investigate the probe-forming capability of an aberration-corrected, three-condenser scanning transmission electron microscope (STEM). Large, minimally convergent and coherent electron probes are useful for a variety of electron diffraction measurements. A three-condenser lens STEM can form a probe either using a virtual aperture below the sample and a virtual source on the sample plane or using a virtual aperture on the sample and a virtual source in the front focal plane. Adding a hexapole probe aberration corrector greatly increases the range of aperture demagnification and thus probe size and convergence angle. We have created probes 0.1 to ∼12 nm in diameter in the simplest operating mode of our STEM, and we calculate that probes as large as 5000 nm that are almost perfectly parallel may be possible in more exotic lens configurations. We have also measured the spatial coherence of some of these probes.
@article{yi_flexible_2010,
	title = {Flexible formation of coherent probes on an aberration-corrected {STEM} with three condensers},
	volume = {59},
	issn = {2050-5698, 2050-5701},
	url = {http://jmicro.oxfordjournals.org.chimie.gate.inist.fr/content/59/S1/S15},
	doi = {10.1093/jmicro/dfq052},
	abstract = {We have used geometric optics calculations and experiments to investigate the probe-forming capability of an aberration-corrected, three-condenser scanning transmission electron microscope (STEM). Large, minimally convergent and coherent electron probes are useful for a variety of electron diffraction measurements. A three-condenser lens STEM can form a probe either using a virtual aperture below the sample and a virtual source on the sample plane or using a virtual aperture on the sample and a virtual source in the front focal plane. Adding a hexapole probe aberration corrector greatly increases the range of aperture demagnification and thus probe size and convergence angle. We have created probes 0.1 to ∼12 nm in diameter in the simplest operating mode of our STEM, and we calculate that probes as large as 5000 nm that are almost perfectly parallel may be possible in more exotic lens configurations. We have also measured the spatial coherence of some of these probes.},
	language = {en},
	number = {S1},
	urldate = {2016-06-12},
	journal = {Journal of Electron Microscopy},
	author = {Yi, Feng and Tiemeijer, Peter and Voyles, Paul M.},
	month = aug,
	year = {2010},
	pmid = {20610414},
	note = {00007 },
	keywords = {Aberration correction, coherence, diffraction, probe formation},
	pages = {S15--S21},
}

Downloads: 0