Open AccessChoosing the optimum accelerating voltage (E O ) to visualize submicron precipitates with a field emission scanning electron microscope
Author(s) -
Hovington Pierre,
Gauvin Raynald,
Drouin Dominique
Publication year - 1997
Publication title -
scanning
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.359
H-Index - 47
eISSN - 1932-8745
pISSN - 0161-0457
DOI - 10.1002/sca.4950190607
Subject(s) - acceleration voltage , scanning electron microscope , electron , context (archaeology) , materials science , monte carlo method , field electron emission , electron microscope , voltage , microscope , field emission microscopy , range (aeronautics) , optics , computational physics , physics , cathode ray , diffraction , mathematics , quantum mechanics , composite material , paleontology , statistics , biology
With the advent of field emission scanning electron microscopes (FESEM), the observation of small phases in the 5 to 50 nm range seems to be possible at low accelerating voltage using backscattered electron imaging mode. In this context, it is important to understand the contrast of multiphased materials at such low energy. A Monte Carlo program to simulate electron trajectories of multiphased materials (CASINO) was used to compute electron backscattering images. Simulations of images for various compositions of spherical precipitates embedded in a homogeneous matrix as a function of precipitate size and accelerating voltage are presented. These simulations show the concept of an optimum accelerating voltage to maximize the contrast of electron backscattering images. The results presented in this paper show that the contrast of backscattering images of multiphased images in the scanning electron microscope is not only a function of the atomic number difference, but that it is also strongly related to the geometry and the size of the phases.