Elastic and inelastic scattering cross-sections of amorphous layers of carbon and vitrified ice

Abstract Elastic and inelastic scattering cross-sections of amorphous layers of carbon and vitrified ice have been determined by electron spectroscopic diffraction (ESD). Using an energy-filtering TEM (EFTEM), elastic and inelastic differential scattering distributions were recorded separately on Image Plates (IP) and quantified. The thickness of carbon films was measured photometrically, that of ice layers by direct imaging. The elastic cross-sections are in good agreement with theory and previous experimental data. The measured inelastic scattering cross-sections are higher than the values derived from theoretical models for free atoms because these models do not account for collective excitations and binding effects. The short mean free path length for inelastic scattering indicates the importance of zero-loss energy filtering for imaging of biological samples embedded in amorphous ice.

[1]  H. G. Heide,et al.  Observations on ice layers , 1984 .

[2]  N. Unwin.  Acetylcholine receptor channel imaged in the open state , 1995, Nature.

[3]  R. Schröder,et al.  A new quasi-confocal image plate scanner with improved spatial resolution and ideal detection efficiency , 1994 .

[4]  R. Schröder.  Zero‐loss energy‐filtered imaging of frozen‐hydrated proteins: model calculations and implications for future developments , 1992, Journal of microscopy.

[5]  J. Dubochet,et al.  Electron microscopy of frozen water and aqueous solutions , 1982 .

[6]  H. Rose,et al.  Simulation of TEM images considering phonon and electronic excitations , 1995 .

[7]  M. F. Smith,et al.  Quantitative energy-filtered electron microscopy of biological molecules in ice. , 1992, Ultramicroscopy.

[8]  Jacques Dubochet,et al.  Electron scattering in ice and organic materials , 1982 .

[9]  R. Henderson.  The potential and limitations of neutrons, electrons and X-rays for atomic resolution microscopy of unstained biological molecules , 1995, Quarterly Reviews of Biophysics.

[10]  R. Leapman,et al.  Water distributions of hydrated biological specimens by valence electron energy loss spectroscopy. , 1993, Ultramicroscopy.

[11]  W. Jahn.  Easily prepared holey films for use in cryo‐electron microscopy , 1995 .

[12]  David B. Williams,et al.  Transmission Electron Microscopy , 1996 .

[13]  H. Rose,et al.  Simulation of filtered and unfiltered TEM images and diffraction patterns , 1995 .

[14]  R. Schröder,et al.  Zero-loss energy filtering as improved imaging mode in cryoelectronmicroscopy of frozen-hydrated specimens☆ , 1990 .

[15]  H. Folger,et al.  Development of 207Pb, 208Pb and 209Bi target wheels in the synthesis of 107Ns, 108Hs and 109Mt , 1993 .

[16]  R. Burge.  Mechanisms of contrast and image formation of biological specimens in the transmission electron microscope , 1973 .

[17]  R. Burge,et al.  The analytical representation of atomic scattering amplitudes for electrons , 1962 .