The Role of Hydrogen in Silicon Microcrystallization

1989 ◽  
Vol 164 ◽  
Author(s):  
S. Wagner ◽  
S.H. Wolff ◽  
J.M. Gibson
Keyword(s):  
Electron Microscope ◽  
Molecular Beam Epitaxy ◽  
Grain Boundary ◽  
Molecular Beam ◽  
Boundary Energy ◽  
Substantial Reduction ◽  
Grain Boundary Energy ◽  
Transmission Electron ◽  
Crystallization Experiments

AbstractWe report and interpret two groups of experiments on the role that hydrogen plays in the formation of silicon microcrystals. We show that the growth of singlecrystal Si by molecular beam epitaxy at 475°C is disrupted by H2, which induces the formation of microcrystals. In crystallization experiments of non-hydrogenated a-Si and of hydrogenated a-Si:H on a hot stage in a transmission electron microscope, hydrogen facilitates the nucleation of crystallites. We explain our observations with a substantial reduction of the grain boundary energy by hydrogen.

Chemical Structure Analysis of a Σ 9 Grain Boundary in α-SiC by Arhvtem

2002 ◽  
Vol 727 ◽  
Author(s):  
Eriko Takuma ◽  
Hideki Ichinose
Keyword(s):  
Silicon Carbide ◽  
Electron Microscope ◽  
Grain Boundary ◽  
Rigid Body ◽  
Chemical Structure ◽  
Boundary Energy ◽  
The Other ◽  
Atomic Resolution ◽  
Grain Boundary Energy ◽  
Transmission Electron

AbstractGrain boundary chemical structure of high purity α silicon carbide was investigated by an atomic resolution high voltage transmission electron microscope (ARHVTEM). Each of a ‘darker’ spots and each of the ‘brighter’ spots in the image have been identified to be silicon (Si) and carbon (C). Two (0001)/(1107) Σ 9 CSL grain boundaries were observed. One boundary showed a rigid body translation of 1/3 <1100> to the component crystals and the other did not. The unit period of the boundary was determined to 2.26 nm along >1120<. Two 6-membered, four 5-membered and 7-membered rings build up the boundary. Each ring consists of three C-C pairs, one Si-Si pair and non-paired Si atoms. In the case without the rigid body translation the number of lone Si atoms are four and only two Si atoms were determined in the other case. The observed structures suggest that the chemical structure of a grain boundary dominantly influences the grain boundary energy.

scholarly journals Molecular Beam Epitaxy of Germanium in the Atomic-Resolution Transmission Electron Microscope

2019 ◽  
Vol 25 (S1) ◽  
pp. 47-48
Author(s):  
Éric Ngo ◽  
Federico Panciera ◽  
Jean-Christophe Harmand ◽  
Weixi Wang ◽  
Martin Foldyna ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Molecular Beam Epitaxy ◽  
Transmission Electron Microscope ◽  
Molecular Beam ◽  
Atomic Resolution ◽  
Transmission Electron

Preferred inclinations of grain boundaries in epitaxially grown bicrystalline thin films of gold

1978 ◽  
Vol 36 (1) ◽  
pp. 434-435
Author(s):  
F. Cosandey ◽  
Y. Komem ◽  
C. L. Bauer
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Boundary Energy ◽  
Boundary Plane ◽  
Boundary Structure ◽  
Structural Elements ◽  
Grain Boundary Energy ◽  
Transmission Electron ◽  
A New Technique ◽  
Misorientation Of Grains

Energy and concomitant structure of grain boundaries are related to inclination of the boundary plane as well as misorientation of grains defining the boundary. Although increasing information is becoming available on variation of grain boundary energy with misorientation, still relatively little is known about variation of grain boundary energy with inclination. The purpose of this research is to examine preferred inclinations of preselected grain boundaries in gold by transmission electron microscopy (TEM) in order to identify principal structural elements and to relate these elements to the energy of special grain boundary configurations.Grain boundaries examined in this research are produced by a new technique involving vapor deposition of gold on common (001) surfaces of bicrystalline substrates of NaCl, characterized by preselected rotation about a common [001] axis, and subsequent epitaxial growth to form a bicrystalline thin film. These films are then removed from their substrates and examined by TEM. The principal advantage of this technique is that the grain boundary is formed during the deposition and growth process, thus resulting in a more perfect boundary structure while eliminating necessity of a separate bonding operation.

The Role of Grain Boundary Energy in Texture Controlled Grain Growth

1992 ◽  
Vol 94-96 ◽  
pp. 391-398 ◽  
Author(s):  
I. Heckelmann ◽  
Giuseppe Carlo Abbruzzese ◽  
K. Lücke
Keyword(s):  
Grain Boundary ◽  
Grain Growth ◽  
Boundary Energy ◽  
Grain Boundary Energy

The Detection of 0.5AT% Boron in Ni3Al Using Parallel Energy Loss Spectroscopy

1990 ◽  
Vol 48 (2) ◽  
pp. 80-81
Author(s):  
C B Boothroyd ◽  
K Sato ◽  
K Yamada
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Grain Boundary ◽  
Energy Loss ◽  
Perchloric Acid ◽  
Background Subtraction ◽  
Ethanol Solution ◽  
Transmission Electron

Recent work has suggested that the improvement in ductility when boron is added to the inherently brittle Ni3Al is caused by the segregation of boron to the grain boundaries and that this seems to be associated with the presence of disordered grain boundary “phases”. In order to clarify the role of boron at Ni3Al boundaries at the resolution of transmission electron microscopy we have developed a method for detecting concentrations as low as 0.5at% of boron in Ni3Al using parallel energy loss spectroscopy.Specimens of Ni-24at%Al with and without 0.5at% B were electropolished in a 20% perchloric acid/ethanol solution and examined at 120 kV in a Philips 420T electron microscope equipped with a Gatan parallel energy loss spectrometer. Figure la shows part of the loss spectrum from the Ni3Al-0.5%B matrix after background subtraction. Provided a high enough count rate can be obtained, the major problem for detecting small edges in energy loss spectra is channel to channel variations in the gain, which for figure la produce a noise level (2σ) of ~0.3%.

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