Tellurite And Fluorotellurite Glasses For Active And Passive

7. Surface properties; MDO 260
Elemental analyses on EDX traces were performed using the ESEM software. The
column aperture diameter was 100 µm for EDX analysis and 30 µm for imaging.
Theory of operation
Images are formed in the SEM by a scanning method. The SEM uses a beam of electrons
to image the sample. Fig. (7.1) illustrates a typical SEM setup.
Fig. (7.1): Schematic of typical SEM setup, where SE = secondary electron, BSE =
backscattered electron, CRT = cathode ray tube, and E-T = Everhart-Thornley [5].
Electrons are produced by thermionic emission from a tungsten filament, and are
accelerated to energies of the range 20-40 keV. The beam is focused onto the surface of
the sample by a number of magnetic lenses, where the beam diameter is typically 2-10
nm [5]. The electron beam is scanned across the sample surface by the scan coils, and a