Surface Morphology of Single-Crystal Ceramics

1986 ◽  
Vol 82 ◽  
Author(s):  
D.W. Susnitzky ◽  
C.B. Carter
Keyword(s):  
Electron Microscope ◽  
Surface Morphology ◽  
Single Crystal ◽  
Total Energy ◽  
Transmission Electron Microscope ◽  
Thin Foil ◽  
Crystalline Materials ◽  
Step Movement ◽  
Thin Foils ◽  
Transmission Electron

ABSTRACTSurfaces of crystalline materials generally facet and form steps and ledges on low-index planes to reduce their total energy. A conventional wedge-shaped transmission electron microscope (TEM) thin foil, prepared slightly misoriented with respect to a low-index plane, provides a suitable geometry for the study of surface ledges, steps and facets. This TEM study characterizes the surface features of annealed thin foils prepared from various oxides with a range of nominally low-index orientations. Observations from single-crystal α-A12O3 and MgAl2O4 (spinel) will be included.The steps and facets typically form along energetically favorable, low-index planes and bound terraces of low-index orientation. The structure of these features are discussed. In addition, surface step movement has been observed and monitored through a series of reannealing experiments on the same foil.

Reconstruction of electron holograms recorded in a non-FEG, non-biprism TEM

1995 ◽  
Vol 53 ◽  
pp. 618-619
Author(s):  
Z.L. Wang
Keyword(s):  
Electron Microscope ◽  
Single Crystal ◽  
Experimental Technique ◽  
Transmission Electron Microscope ◽  
The Other ◽  
Electron Holography ◽  
Transmission Electron ◽  
Coherent Sources ◽  
Imaging Theory ◽  
Normal Specimen

An experimental technique for performing electron holography using a non-FEG, non-biprism transmission electron microscope (TEM) has been introduced by Ru et al. A double stacked specimens, one being a single crystal foil and the other the specimen, are loaded in the normal specimen position in TEM. The single crystal, which is placed onto the specimen, is responsible to produce two beams that are equivalent to two virtual coherent sources illuminating the specimen beneath, thus, permitting electron holography of the specimen. In this paper, the imaging theory of this technique is described. Procedures are introduced for digitally reconstructing the holograms.

Observation of dislocations in dynamically loaded Cu-SiO2

1986 ◽  
Vol 44 ◽  
pp. 424-425
Author(s):  
D. S. Pritchard
Keyword(s):  
Electron Microscope ◽  
Strain Rate ◽  
Single Crystal ◽  
Transmission Electron Microscope ◽  
Volume Fraction ◽  
Screw Dislocations ◽  
Spherical Inclusions ◽  
Transmission Electron ◽  
Crystal Dispersion ◽  
Strain Rate Loading

The effect of varying the strain rate loading conditions in compression on a copper single crystal dispersion-hardened with SiO2 particles has been examined. These particles appear as small spherical inclusions in the copper lattice and have a volume fraction of 0.6%. The structure of representative crystals was examined prior to any testing on a transmission electron microscope (TEM) to determine the nature of the dislocations initially present in the tested crystals. Only a few scattered edge and screw dislocations were viewed in those specimens.

Development of a Mach-Zehnder type electron interferometer on a 1.2-MV field-emission transmission electron microscope

Microscopy ◽  
2020 ◽  
Vol 69 (6) ◽  
pp. 411-416
Author(s):  
Tetsuya Akashi ◽  
Yoshio Takahashi ◽  
Ken Harada
Keyword(s):  
Electron Microscope ◽  
Single Crystal ◽  
Single Crystals ◽  
Field Emission ◽  
Transmission Electron Microscope ◽  
Beam Splitters ◽  
Interference Fringes ◽  
Transmission Electron ◽  
Performance Results

Abstract We have developed an amplitude-division type Mach-Zehnder electron interferometer (MZ-EI). The developed MZ-EI is composed of single crystals corresponding to amplitude-division beam splitters, lenses corresponding to mirrors and an objective aperture. The spacings and azimuth angles of interference fringes can be controlled by single crystal materials and their orientations and by diffraction spots selected by the objective aperture. We built the MZ-EI on a 1.2-MV field-emission transmission electron microscope and tested its performance. Results showed that interference fringes were created for various spacings and azimuth angles, which demonstrates the practicability of the MZ-EI as an amplitude-division type electron interferometer.

Cross‐section transmission electron microscope observations of diamond‐turned single‐crystal Si surfaces

1994 ◽  
Vol 65 (20) ◽  
pp. 2553-2555 ◽  
Author(s):  
Takayuki Shibata ◽  
Atsushi Ono ◽  
Kenji Kurihara ◽  
Eiji Makino ◽  
Masayuki Ikeda
Keyword(s):  
Electron Microscope ◽  
Single Crystal ◽  
Cross Section ◽  
Transmission Electron Microscope ◽  
Transmission Electron

scholarly journals Deformation Mechanisms and Fracture of Ni-Based Metallic Glasses

2016 ◽  
Vol 61 (2) ◽  
pp. 791-796 ◽  
Author(s):  
S. Lesz ◽  
S. Griner ◽  
R. Nowosielski
Keyword(s):  
Electron Microscope ◽  
Optical Microscopy ◽  
Metallic Glasses ◽  
Thin Foil ◽  
Tensile Tests ◽  
Deformation Mechanisms ◽  
X Ray ◽  
Fracture Surfaces ◽  
Thin Foils ◽  
Transmission Electron

Abstract The cracking of materials and fracture surface is of great practical and academic importance. Over the last few years the development of the fractography of crystalline alloys resulted in a useful tool for the prediction or failure analysis. Many attempts have been made to observe cracks using optical microscopy, X-ray topography and transmission electron microscopy (TEM). Of these techniques, the resolution of optical microscopy and X-ray topography is too poor. By contrast, the resolution of TEM is high enough for detailed information to be obtained. However, in order to apply TEM observations, a thin foil specimen must be prepared, and it is usually extremely difficult to prepare such a specimen from a pre-selected region containing a crack. In the present work, deformation mechanisms fracture surfaces of Ni-based metallic glass samples have been studied by specially designed experiments. In order to study the deformation mechanisms and fracture the Ni-based metallic glasses have been investigated in the tensile test. The structure and fracture surfaces after the decohesion process in tensile tests were observed using transmission electron microscope (TEM) and scanning electron microscope (SEM), respectively. The studies of structure were performed on thin foils. Moreover the investigated tape was subjected to a banding test. Then, the tape was straightened and the thin foil from the area of maximum strain was prepared. This thin foil sample was deformed before the TEM investigation to obtain local tears.

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