Abstract
The new measuring technique using electron holography was applied to various measurements of materials. Electron holography is a two-step imaging method. In the first step, interference image is formed in a field emission electron microscope by superimposing a reference electron wave on an object electron wave which transmitted through a specimen. In the second step, the optical image is reconstructed in an optical interferometer. Among several applications of this technique, interference microscopy in particular was proven to be promising for practical measurements, since this technique enables to measure phase distribution of an object wave by interference between the reconstructed image and a reference laser beam.
The distribution of fringes in an optical interference micrograph indicated the thickness distribution of a homogeneous specimen and the magnetic lines of force inside and outside of a ferromagnetic materials. This paper describes the experimental results such as distribution measurements of thickness and magnetization in thin films and fine particles, direct observation of quantized magnetic fluxes and surface morphology of crystal specimen.
The potentiality of this technique was clearly demonstrated and further developments of electron holography are expected to open new possibilities of observation and measurements in atomic dimensions.
