Imaging of three-dimensional objects in emission electron microscopy

Under investigation by emission electron microscopy, the shape and size of three-dimensional objects are distorted because of the appearance of a char acteristic potential relief and a possible contact potential difference bet ween the particles and the substrate. An estimation of these effects for sp herical particles is made. It is shown that the apparent size of particles observed in an emission electron microscope (EEM) could be increased as wel l as decreased depending on the relation between the work functions of the particle and the substrate. The corresponding formulae are given and severa l possibilities are shown which permit us to determine from the EEM image t he real size of particles and their work function relative to the substrate .