Variations in Backscattered Electron (BSE) Images with a Scanning Electron Microscope (SEM) as Applied to Mineral Grains and Excrements in a Podzol, To Precipitates on a Water-Tube Filter and to Bauxite

Abstract Bisdom, E.B.A., Thiel, F., Volbert, B. and Jackman, J., 1983. Variations in backscattered electron (BSE) images with a Scanning Electron Microscope (SEM) as applied to mineral grains and excrements in a podzol, to precipitates on a water-tube filter and to bauxite. Geoderma, 30: 93–116. The results of experiments on various materials in thin sections, using a Scanning Electron Microscope with a secondary electron detector and four backscattered electron detectors, are discussed. The Multi-Function-Detector (MFD) system for backscattered electrons allows the observation of the 'real' topography in a thin section with the SE-BSE mode and is also able to give good information on the contrasts in materials (atomic contrasts) with the BSE (A+B) mode. Various other possibilities are also present with this system, e.g. the study of soil materials over different depths below the surface of a thin section. Of considerable interest is the possibility to start the investigation of thin sections at X 10 magnification without the loss of part of the picture on the display screen or micrograph. As a consequence, interpretational steps from the field observations to light microscopy and submicroscopy will most probably become easier in the near future. Maximum magnifications using the BSE-signal were dependent on the type of analysed material, but were usually significantly higher than with older backscattered electron detector systems.