Reflection shadow imaging of crystal surface by low-voltage point-reflection electron microscopy

1998 ◽  
Vol 72 (1-2) ◽  
pp. 67-81 ◽  
Author(s):  
Xu Zhang ◽  
Uwe Weierstall ◽  
John C.H. Spence
Keyword(s):  
Electron Microscopy ◽  
Low Voltage ◽  
Crystal Surface ◽  
Point Reflection ◽  
Shadow Imaging ◽  
Reflection Electron Microscopy

Studies of Oxide Formation on Copper Thin Films by Electron Microscopy

1977 ◽  
Vol 35 ◽  
pp. 316-317
Author(s):  
G. G. Hembree ◽  
M. A. Otooni ◽  
J. M. Cowley
Keyword(s):  
Electron Microscopy ◽  
Electron Diffraction ◽  
Single Crystal ◽  
Crystal Surface ◽  
Crystal Defects ◽  
Diffraction Reflection ◽  
Reaction Products ◽  
Intermediate Energies ◽  
Crystal Films ◽  
Reflection Electron Microscopy

The formation of oxide structures on single crystal films of metals has been investigated using the REMEDIE system (for Reflection Electron Microscopy and Electron Diffraction at Intermediate Energies) (1). Using this instrument scanning images can be obtained with a 5 to 15keV incident electron beam by collecting either secondary or diffracted electrons from the crystal surface (2). It is particularly suited to studies of the present sort where the surface reactions are strongly related to surface morphology and crystal defects and the growth of reaction products is inhomogeneous and not adequately described in terms of a single parameter. Observation of the samples has also been made by reflection electron diffraction, reflection electron microscopy and replication techniques in a JEM-100B electron microscope.A thin single crystal film of copper, epitaxially grown on NaCl of (100) orientation, was repositioned on a large copper single crystal of (111) orientation.

Experiments on REM and SREM using a Tem/Stem Microscope with a Configurable Angle-Resolving Detector

1990 ◽  
Vol 48 (1) ◽  
pp. 338-339
Author(s):  
H. Banzhof ◽  
I. Daberkow
Keyword(s):  
Electron Microscopy ◽  
Single Crystal ◽  
Crystal Surface ◽  
High Energy ◽  
Contrast Effects ◽  
Atomic Steps ◽  
Single Crystal Surfaces ◽  
Platinum Single Crystal ◽  
Reflection Electron Microscopy ◽  
Beam Reflection

A Philips EM 420 electron microscope equipped with a field emission gun and an external STEM unit was used to compare images of single crystal surfaces taken by conventional reflection electron microscopy (REM) and scanning reflection electron microscopy (SREM). In addition an angle-resolving detector system developed by Daberkow and Herrmann was used to record SREM images with the detector shape adjusted to different details of the convergent beam reflection high energy electron diffraction (CBRHEED) pattern.Platinum single crystal spheres with smooth facets, prepared by melting a thin Pt wire in an oxyhydrogen flame, served as objects. Fig. 1 gives a conventional REM image of a (111)Pt single crystal surface, while Fig. 2 shows a SREM record of the same area. Both images were taken with the (555) reflection near the azimuth. A comparison shows that the contrast effects of atomic steps are similar for both techniques, although the depth of focus of the SREM image is reduced as a result of the large illuminating aperture. But differences are observed at the lengthened images of small depressions and protrusions formed by atomic steps, which give a symmetrical contrast profile in the REM image, while an asymmetric black-white contrast is observed in the SREM micrograph. Furthermore the irregular structures which may be seen in the middle of Fig. 2 are not visible in the REM image, although it was taken after the SREM record.

Surface resonance channelling in scanning reflection electron microscopy

1988 ◽  
Vol 46 ◽  
pp. 692-693
Author(s):  
J.M. Cowley ◽  
P.A. Crozier
Keyword(s):  
Electron Microscopy ◽  
Crystal Surface ◽  
Scanning Transmission Electron Microscope ◽  
Diffraction Effect ◽  
Transmission Electron ◽  
Surface Resonance ◽  
Scanning Transmission ◽  
Reflection Electron Microscopy ◽  
Resolution Imaging ◽  
Electron Energy Loss

The phenomena of the channelling of electrons along planes or rows of atoms in the surface layers of crystals has been investigated recently in relation to microdiffraction and RHEED, REM, (reflection electron microscopy) and REELS (reflection electron energy loss spectroscopy) by using a conventional TEM in the reflection mode.The renewed interest in this phenomenon, known for many years, is the evidence from calculations of dynamical diffraction effect at surfaces that the electrons may be channelled along the topmost layers of atoms on a crystal surface and that the RHEED, REM and REELS signals may thus be sensitive to the structure and composition of the surface layer. These techniques may therefore provide a powerful new approach to the study of surfaces in which surface microanalysis and diffraction studies may be combined with nanometer-resolution imaging.An investigation has now been made of the analogous techniques which may be applied to the study of surfaces by use of a scanning transmission electron microscope.

Atomic inner shell excitations with eels in REM: Pt and Au M4,5 edge shapes modifications in REM

1987 ◽  
Vol 45 ◽  
pp. 402-403
Author(s):  
Z.L. Wang ◽  
J.M. Cowley
Keyword(s):  
Electron Microscopy ◽  
Energy Loss ◽  
Surface Plasmon ◽  
Crystal Surface ◽  
Metal Foil ◽  
Shape Modification ◽  
Bulk Single Crystals ◽  
Reflection Electron Microscopy ◽  
Thin Metal Foil ◽  
Electron Energy Loss

Electron energy-loss spectroscopy (EELS) has been used in parallel with reflection electron microscopy (REM) to investigate the inner shell structure of the surface atoms in bulk single crystals of Pt and Au. A Phillips 400T TEM is used for the experiment, with the arrangement shown in fig. 4. The observed M4,5 edge from the bulk crystal surface (REM case) is compared with that from a thin metal foil (TEM case), such that the surface atomic inner shell modifications, relative to the atoms in the bulk, can be obtained. Fig. 1(A) and 1(B) show the REM image of the Pt (111) surface and the corresponding EELS Pt-M4,5 edge. This observed edge in the REM case is compared with the edge observed in the TEM from a thin Pt foil (fig.l(B)). Comparing the results in fig 1(B) and fig. 2(B) for the REM and TEM cases, the shape modification at the M4,5 edge maximum part is related to the strong multiple surface plasmon scattering[l].

Reflection electron microscopy of ferroelectric domains

1994 ◽  
Vol 52 ◽  
pp. 568-569
Author(s):  
Feng Tsai ◽  
J. M. Cowley
Keyword(s):  
Electron Microscopy ◽  
Surface Defects ◽  
Crystal Surface ◽  
Dark Field ◽  
Ferroelectric Domain ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Crystal Surfaces ◽  
Domain Boundaries ◽  
Reflection Electron Microscopy

The intersections of ferroelectric domain boundaries with crystal surfaces have been studied by optical microscopy. The method is widely used but usually of low resolution. Transmission electron microscopy (TEM) can provide high-resolution images but may not be appropriate for studying crystal surfaces. Scanning electron microscopy (SEM) has also been used to study the intersections of ferroelectric domain boundaries with the surfaces of ferroelectric crystals. However, the resolution is still low and is destructive if an etched crystal surface is used. Other alternatives have also been attempted to study ferroelectric domain boundaries on surfaces, such as scanning tunneling microscopy (STM), atomic force microscopy (AFM). But, no reports have been known so far.On the other hand, reflection electron microscopy (REM), as a branch of dark-field imaging technique dedicated for surface studies in TEM, has been developed to study crystal surfaces, surface reconstruction and surface defects with a resolution of about 10Å. It has been considered as a powerful technique to study surface defects and may be used to study the ferroelectric domain boundaries emerging on surfaces.

Surface Characterization by Reflection Electron Microscopy (REM)

1984 ◽  
Vol 41 ◽  
Author(s):  
Tung Hsu ◽  
J. M. Cowley
Keyword(s):  
Electron Microscopy ◽  
Surface Characterization ◽  
Crystal Surface ◽  
Stacking Faults ◽  
High Sensitivity ◽  
High Energy ◽  
Surface Layers ◽  
High Energy Electrons ◽  
Unique Method ◽  
Reflection Electron Microscopy

AbstractReflection electron microscopy (REM) utilizes the Bragg reflected high energy electrons to form the image of a crystal surface. Images of dislocations, atomic steps, reconstructions of surface layers of atoms and adatoms, stacking faults and twinning, superlattices, etc., have been successfully observed on a wide variety of specimens. Contrast is mainly due to diffraction and phase, which distiguished REM as a unique method for high spacial resolution and high sensitivity imaging of the surfaces of bulk specimens. REM can be effectively performed under UHV as well as under the moderate vacuum of an ordinary commercial electron microscope.

LOW ENERGY POINT REFLECTION ELECTRON MICROSCOPY

1997 ◽  
Vol 04 (03) ◽  
pp. 577-587 ◽  
Author(s):  
J. C. H. SPENCE ◽  
X. ZHANG ◽  
U. WEIERSTALL ◽  
J. M. ZUO ◽  
E. MUNRO ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Low Energy ◽  
Energy Point ◽  
Point Reflection ◽  
Reflection Electron Microscopy

Processing of human melanoma cells for correlative TEM, LVSEM, and LM

1991 ◽  
Vol 49 ◽  
pp. 106-107
Author(s):  
Marek Malecki ◽  
J. Victor Small ◽  
James Pawley
Keyword(s):  
Electron Microscopy ◽  
Low Voltage ◽  
Fluorescent Microscopy ◽  
Blood Stream ◽  
Surface Topology ◽  
Integrin Receptors ◽  
Transmission Electron ◽  
Develop Technology ◽  
Voltage Scanning ◽  
Mechanisms Of Adhesion

The relative roles of adhesion and locomotion in malignancy have yet to be clearly established. In a tumor, subpopulations of cells may be recognized according to their capacity to invade neighbouring tissue,or to enter the blood stream and metastasize. The mechanisms of adhesion and locomotion are themselves tightly linked to the cytoskeletal apparatus and cell surface topology, including expression of integrin receptors. In our studies on melanomas with Fluorescent Microscopy (FM) and Cell Sorter(FACS), we noticed that cells in cultures derived from metastases had more numerous actin bundles, then cells from primary foci. Following this track, we attempted to develop technology allowing to compare ultrastructure of these cells using correlative Transmission Electron Microscopy(TEM) and Low Voltage Scanning Electron Microscopy(LVSEM).

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