A Novel Phase-contrast Transmission Electron Microscopy Producing High-contrast Topographic Images of Weak objects
Tóm tắt
We report a novel class of transmission electron microscope (TEM), the difference-contrast electron microscope (DTEM), which displays nanostructures of thin specimen objects in a topographical manner. Topography obtained by the difference-contrast develops shadowgraphs in pseudo three-dimension, namely volume-like representation of projected objects as if things are illuminated by light from one direction. The specific optical device tomanipulate electron waves for DTEM is the hemicircular π phase-plate, which appears to be quite distinguishable from the Zernike phase plate utilized in Zernike phase-contrast TEM, while both have to be placed onto the back-focal plane of the objective lens. The topographic images obtained with DTEM for ultrathin sections of kidney cells were compared with those obtained with conventional TEM. DTEM confirmed the experimental advantage of high contrast topography by visualizing ultrastructural details inside the cells.
Tài liệu tham khảo
Reimer, L.: Transmission Electron Microscopy(4th ed.), Springer-Verlag, Berlin, 1997.
Kanaya, K.and Kawakatsu, H.: Experiment on the Electron Phase Microscope, J. Appl. Phys. 29 (1958), 1046–1049.
Badde, H.G.and Reimer, L.: Der Einflus Einer Streuenden Phase platte auf das Elektronmikroskopische Bild, Z. Naturforsch 25a (1970), 760–765.
Johnson, H.M.: In: H.A. Hayat (ed.), Principlesand Techniques of Electron Microscopy, 3, pp. 153–198, Van Nostrand Reinhold Co., New York, 1973.
Danev, R. and Nagayama, K.: Transmission Electron Microscopy with Zernike Phase Plate, Ultramicroscopy 88 (2001), 243–252.
Spencer, M.: Fundamentals of Light Microscopy, CambridgeUniv. Press, London, 1982.
Willash, D.: High ResolutionElectronMicroscopy with Profiled Phase Plates, Optik 44 (1975), 17–36.
Danev, R. and Nagayama, K., J. Electr.Microsc., to be submitted.
Danov, K., Danev, R. and Nagayama, K.: Electric Charging of Thin Films measured using the Contrast Transfer Function, Ultramicrosocpy 87 (2001), 45–54.
Danov, K. Danev, R. and Nagayama, K.:Reconstruction of the Electric Charge Density in Thin Films from the Contrast Transfer Function Measurement, Ultramicroscopy, in press.
Danev, R. and Nagayama, K.: Complex Observation in ElectronMicroscopy. II. Direct Visualization of Phases and Amplitudes of Exit Wave Functions, J. Phys. Soc. Jpn. 70 (2001), 696–702.