ELECTRON-HOLOGRAPHIC INTERFERENCE MICROSCOPY

Recent developments in electron interference microscopy are introduced based on holography principles. This technique has been given a major boost due to the development of a coherent field-emission electron be am. This has facilitated the measurement of the phase distribution of an electron beam transmitted through or reflected from an object to wi thin 1/100 of the electron wavelength. Phase distribution can be displ ayed as a phase contour map in an electron micrograph. There the conto ur fringes directly and quantitatively indicate the thickness contours of a uniform sample, magnetic lines of force of a magnetic sample and equipotential lines of an electrostatic sample. Microscopic objects o r fields have made their appearance in amplified interference microgra phs through the use of this technique. Specific examples are the stati c and even dynamic observation of magnetic fluxons penetrating a super conductor and the quantitative measurement of specimen thickness or to pography in atomic dimensions.