Techniques for Characterising Artificial Layer Structures using Transmission Electron Microscopy

1987 ◽  
Vol 103 ◽  
Author(s):  
W. M. Stobbs
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Structural Changes ◽  
Dark Field ◽  
Multilayer Structures ◽  
Dark Field Imaging ◽  
Transmission Electron ◽  
Layer Structures ◽  
Quantitative Characterisation ◽  
Field Imaging

ABSTRACTT.E.M. methods are described for the quantitative characterisation of the compositional and structural changes at interfaces and in homo- and hetero-phase multilayer structures. Many of the newer approaches described including the Fresnel and Centre Stop Dark Field Imaging Methods were developed specifically for such characterisations. The range of applications of each of the techniques is assessed as is the importance of delineating the limiting effects of inelastic and inelastic/elastic multiple scattering.

scholarly journals Annular Dark Field Imaging of Catalyst Nanoparticles in Single Shot Dynamic Transmission Electron Microscopy

2009 ◽  
Vol 15 (S2) ◽  
pp. 1082-1083
Author(s):  
D Masiel ◽  
B Reed ◽  
T LaGrange ◽  
ND Browning
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Dark Field ◽  
Single Shot ◽  
Catalyst Nanoparticles ◽  
Dark Field Imaging ◽  
Transmission Electron ◽  
Annular Dark Field ◽  
Field Imaging

Extended abstract of a paper presented at Microscopy and Microanalysis 2009 in Richmond, Virginia, USA, July 26 – July 30, 2009

Crystalline Morphologies of Polychloroprene Thin Films as Revealed by Transmission Electron Microscopy Observation

1999 ◽  
Vol 14 (4) ◽  
pp. 1645-1652 ◽  
Author(s):  
Toshiki Shimizu ◽  
Masaki Tsuji ◽  
Shinzo Kohjiya
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Dark Field ◽  
Bright Field Image ◽  
Dark Field Imaging ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Lamellar Crystals ◽  
Field Imaging

Thin films of polychloroprene (CR; Neoprene-W) were made by casting its solution (2.0 wt%) in benzene onto the water surface, and some of them were stretched by a desired amount of strain (ε) in their “molten” state. The specimens thus prepared were then crystallized and examined by transmission electron microscopy. Morphological observations in bright- and dark-field imaging modes and selected-area electron diffraction analysis revealed directly that filamentous entities observed in the bright-field image are the edge-on lamellar crystals. It was, therefore, confirmed that the morphological results obtained from the thin specimens of CR without any electron staining are basically in accord with those reported so far for the OsO4-stained thin films of CR.

Origin of Threefold Periodicity in High-Resolution Transmission Electron Microscopy Images of Thin Film Cubic SiC

1999 ◽  
Vol 5 (6) ◽  
pp. 420-427 ◽  
Author(s):  
U. Kaiser ◽  
A. Chuvilin ◽  
P.D. Brown ◽  
W. Richter
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Molecular Beam ◽  
Dark Field ◽  
Dark Field Imaging ◽  
Transmission Electron ◽  
Field Imaging ◽  
Microscopy Images ◽  
Image Simulations

Abstract: High-resolution transmission electron microscopy (HRTEM) images of the [1–10] zone of cubic SiC layers grown by molecular beam epitaxy (MBE) often reveal regions of material exhibiting an unusual threefold periodicity. The same contrast was found in earlier works of Jepps and Page, who attributed this contrast in HRTEM images of polycrystalline SiC to the 9R-SiC polytype. In this report we demonstrate by HRTEM image simulations that the model of the 9R polytype and an alternative twinning model can fit qualitatively the experimental HRTEM images. However, by comparing the fast Fourier transform (FFT) patterns of the experiments and the simulations, as well as by using dark-field imaging, we show unambiguously that only the model of overlapping twinned 3C-SiC crystals fully agrees with the experiments.

Minerals and Aligned Collagen Fibrils in Tilapia Fish Scales: Structural Analysis Using Dark-Field and Energy-Filtered Transmission Electron Microscopy and Electron Tomography

2011 ◽  
Vol 17 (5) ◽  
pp. 788-798 ◽  
Author(s):  
Mitsuhiro Okuda ◽  
Nobuhiro Ogawa ◽  
Masaki Takeguchi ◽  
Ayako Hashimoto ◽  
Motohiro Tagaya ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Tomography ◽  
Dark Field ◽  
Collagen Fibrils ◽  
Internal Layer ◽  
Dark Field Imaging ◽  
Transmission Electron ◽  
The Matrix ◽  
Field Imaging

AbstractThe mineralized structure of aligned collagen fibrils in a tilapia fish scale was investigated using transmission electron microscopy (TEM) techniques after a thin sample was prepared using aqueous techniques. Electron diffraction and electron energy loss spectroscopy data indicated that a mineralized internal layer consisting of aligned collagen fibrils contains hydroxyapatite crystals. Bright-field imaging, dark-field imaging, and energy-filtered TEM showed that the hydroxyapatite was mainly distributed in the hole zones of the aligned collagen fibrils structure, while needle-like materials composed of calcium compounds including hydroxyapatite existed in the mineralized internal layer. Dark-field imaging and three-dimensional observation using electron tomography revealed that hydroxyapatite and needle-like materials were mainly found in the matrix between the collagen fibrils. It was observed that hydroxyapatite and needle-like materials were preferentially distributed on the surface of the hole zones in the aligned collagen fibrils structure and in the matrix between the collagen fibrils in the mineralized internal layer of the scale.

SURFACE TRANSMISSION ELECTRON MICROSCOPY ON STRUCTURES WITH TRUNCATION

1997 ◽  
Vol 04 (04) ◽  
pp. 687-694 ◽  
Author(s):  
KUNIO TAKAYANAGI ◽  
YOSHITAKA NAITOH ◽  
YOSHIFUMI OSHIMA ◽  
MASANORI MITOME
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Dark Field ◽  
Scanning Tunneling ◽  
Plan View ◽  
Step Motion ◽  
Dark Field Imaging ◽  
Surface Steps ◽  
Transmission Electron

Surface transmission electron microscopy (TEM) has been used to reveal surface steps and structures by bright and dark field imaging, and high resolution plan view and/or profile view imaging. Dynamic processes on surfaces, such as step motion, surface phase transitions and film growths, are visualized by a TV system attached to the electron microscope. Atom positions can precisely be detected by convergent beam illumination (CBI) of high resolution surface TEM. Imaging of the atomic positions of surfaces with truncation is briefly reviewed in this paper, with recent development of a TEM–STM (scanning tunneling microscope) system.

scholarly journals The nanometre-scale physiology of bone: steric modelling and scanning transmission electron microscopy of collagen–mineral structure

2012 ◽  
Vol 9 (73) ◽  
pp. 1774-1786 ◽  
Author(s):  
Benjamin Alexander ◽  
Tyrone L. Daulton ◽  
Guy M. Genin ◽  
Justin Lipner ◽  
Jill D. Pasteris ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Scanning Transmission Electron Microscopy ◽  
Dark Field ◽  
Collagen Fibrils ◽  
Scanning Transmission Electron ◽  
Dark Field Imaging ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Collagen Molecules

The nanometre-scale structure of collagen and bioapatite within bone establishes bone's physical properties, including strength and toughness. However, the nanostructural organization within bone is not well known and is debated. Widely accepted models hypothesize that apatite mineral (‘bioapatite’) is present predominantly inside collagen fibrils: in ‘gap channels’ between abutting collagen molecules, and in ‘intermolecular spaces’ between adjacent collagen molecules. However, recent studies report evidence of substantial extrafibrillar bioapatite, challenging this hypothesis. We studied the nanostructure of bioapatite and collagen in mouse bones by scanning transmission electron microscopy (STEM) using electron energy loss spectroscopy and high-angle annular dark-field imaging. Additionally, we developed a steric model to estimate the packing density of bioapatite within gap channels. Our steric model and STEM results constrain the fraction of total bioapatite in bone that is distributed within fibrils at less than or equal to 0.42 inside gap channels and less than or equal to 0.28 inside intermolecular overlap regions. Therefore, a significant fraction of bone's bioapatite (greater than or equal to 0.3) must be external to the fibrils. Furthermore, we observe extrafibrillar bioapatite between non-mineralized collagen fibrils, suggesting that initial bioapatite nucleation and growth are not confined to the gap channels as hypothesized in some models. These results have important implications for the mechanics of partially mineralized and developing tissues.

Electron microscopy of high performance PBO and ABPBO polymers

1984 ◽  
Vol 42 ◽  
pp. 382-383
Author(s):  
S. J. Krause ◽  
T. Haddock ◽  
W. W. Adams
Keyword(s):  
Electron Microscopy ◽  
High Performance ◽  
Dark Field ◽  
Dark Field Imaging ◽  
Transmission Electron ◽  
Recent Developments ◽  
Flexible Coil ◽  
Rigid Rod ◽  
Field Imaging ◽  
Beam Damage

Recent developments in the synthesis and preparation of high molecular weight polymers have resulted in the generation of two new aromatic heterocyclic polymers with excellent mechanical properties. The polymers are the rigid rod poly-p-phenylene benzobisoxazole (PBO) and the flexible coil poly 2,5(6) benzoxazole (ABPBO). The purpose of this study was to characterize the morphology of PBO and ABPBO in as-spun (AS) and annealed (AN) conditions by the use of transmission electron microscopy (TEM) imaging and diffraction techniques, and to compare the results with other high performance polymers.Samples were prepared for TEM by detachment replication. A JEOL 100CX was operated at 120 kV. Dark field images were formed from the first, second, and third equatorial reflections in the case of PBO, and from the first and second equatorial reflections for ABPBO. In order to minimize beam damage artifacts, the areas of the sample used for dark field imaging were adjacent to those used for locating and focusing.

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