1. Scanning Electron Microscopy

2. Applications of SEM Visualizing smaller resolutions than visible microscopy can (resolutions of ~25Å are possible) 130,000x magnification Morphological and Chemical data can be attained Physical properties such as conductivity can be found

3. Sample Preparation Must be conductive Must not be volatile Sputtering with metals Freeze drying (fracturing/etching)

4. Electron source

5. Electric Optics Used to create a beam analogous to a LASER Uses electric and magnetic (B) fields to focus electrons Width of beam at sample determines power

7. Detection Scintilator/photomultiplier tube for backscatter and secondary Semiconductor probes for X-rays Ammeter for current Each mode gathers different information

8. Imaging Modes Secondary Electron Backscatter X-ray Dispersive Sample current

9. Topographical Information Sharper, deeper field images than backscatter Appears to be illuminated from an angle Most common technique Secondary Electron

10. Backscatter Topographical information (less 3D information than secondary) Compositional information Backscatter is proportional to atomic mass Mmm Doughnuts

11. X-ray Dispersive Compositional information Compositional information

12. References and picture sources http://mse.iastate.edu/microscopy/college.htmlhttp://www.sem.com/analytic/sem.htm A Removable Conductive Coating for Scanning Electron Microscopy, by Allan A. Mills Studies in Conservation © 1989 International Institute for Conservation of Historic and Artistic Works 75-79 J. W. Hudgins; Trygve Krekling; Vincent R. Franceschi. “Distribution of Calcium Oxalate Crystals in the Secondary Phloem of Conifers: A Constitutive Defense Mechanism?” New Phytologist, Vol. 159, No. 3. (Sep., 2003), pp. 677- 690. http://nhml.com/resources_NHML_Scanning-Electron-Microscopes.phphttp://www.geo.vu.nl/~smit/forums/CL-TL-SEMimaging.htmlhttp://www.quorumtech.com/Applications/Cryo_Apps_Library/Arabidopsis.htmhttp://www.siliconcert.com/eds.htm