The Electron Optical Characteristics of a Special Cathode Coated by LaB₆ Films Made by Ion Bean Sputter Deposition for High Resolution Scanning Electron Microscops

Abstract

This paper describes an experimental inverstigation of the thermionic emission properties of tungsten hairpin filament coated with lanthanum hexaboride films (LaB₆) by meams of ion beam sputter deposition method.
Measurement of brightness of the coated filament was parformed in a scanning electron microscope. As a result, the brightness of about 3.42×10⁴ A/cm²·ster. (20 kV), was obtained by LaB₆ coated tungsten hairpin filament.
Furthermore, it was found that resolution measured from the intervals between latexes obtained by S-450 (SEM) with LaB₆ coated was about 20 nm.