Atomic and Electronic Structures of Grain Boundary in Chemical Vapor Deposited Diamond Thin Film

1995 ◽  
Vol 416 ◽  
Author(s):  
Y. Zhang ◽  
H. Ichinose ◽  
Y. Ishida ◽  
K. Ito ◽  
M. Nakanose
Keyword(s):  
Grain Boundary ◽  
Energy Loss ◽  
Electron Energy ◽  
Electronic Structures ◽  
Chemical Vapor ◽  
High Resolution Electron Microscopy ◽  
Boundary Structure ◽  
Atomic Structures ◽  
Tilt Boundaries ◽  
Electron Energy Loss

ABSTRACTHigh resolution electron microscopy and electron energy-loss spectrometry were used to investigate both atomic and electronic structures of grain boundaries in diamond thin films grown by chemical vapor deposition. The atomic structures of {112}σ3 and {114}σ9 <110= tilt boundaries in diamond show different features from those in other diamond structure semiconductors. The electron energy-loss spectra recorded from the grain boundary regions show extra intensity near the energy-loss corresponding to carbon 1s-to-π*; transition, as compared to the spectra recorded from neighboring crystalline regions. This gives the evidence that the dangling bonds are not fully reconstructed along <110= direction in the boundary structure. Atomic models are constructed for these boundaries with the presence of non-tetracoordinated atoms. The stability of the boundary structure is explained by the π-like bonding between the nontetracoordinated atoms.

Application of Spatially Resolved Eels on Atomic Structure Determination of Diamond Grain Boundary

1996 ◽  
Vol 466 ◽  
Author(s):  
H. Ichinose ◽  
Y. Zhang ◽  
Y. Ishida ◽  
K. Ito ◽  
M. Nakanose
Keyword(s):  
Grain Boundary ◽  
Energy Loss ◽  
Electron Energy ◽  
Atomic Structure ◽  
Chemical Vapor ◽  
Structure Information ◽  
Spatially Resolved ◽  
Electron Energy Loss Spectrometry ◽  
Diamond Grain ◽  
Electron Energy Loss

ABSTRACTA new spatially resolved electron energy-loss spectrometry (EELS) method was introduced to obtain atomic structure information of grain boundaries in diamond thin films grown by chemical vapor deposition. The electron energy-loss spectra recorded from the grain boundary regions showed different feature near the energy loss corresponding to carbon ls-to-π* transition, as compared to the spectra recorded from neighboring crystalline regions. This difference was attributed to dangling bonds in atoms with planar three-fold coordination. A series of experiments are described in this paper that exclude any possible artifact in result interpretation.

Investigating Ca Segregated to a Grain Boundaries in MgO Using Multiple Scattering Analysis of Electron Energy Loss Spectra

1998 ◽  
Vol 4 (S2) ◽  
pp. 776-777
Author(s):  
J. P. Buban ◽  
J. Zaborac ◽  
H. Moltaji ◽  
G. Duscher ◽  
N. D. Browning
Keyword(s):  
Energy Loss ◽  
Grain Boundaries ◽  
Electron Energy ◽  
Structural Model ◽  
Boundary Structure ◽  
Structure Property ◽  
Contrast Imaging ◽  
Scale Properties ◽  
Z Contrast ◽  
Electron Energy Loss

Although grain boundaries typically account for only a small fraction of a material, they can have far reaching effects on the overall bulk scale properties. These effects are usually simply linked to the boundary having a different atomic arrangement to the bulk. A necessary first step in understanding the structure-property relationships is therefore a detailed determination of the boundary structure.One means of obtaining detailed information on the structure of grain boundaries is through correlated Z-contrast imaging and electron energy loss spectroscopy (EELS). The Z-contrast image generates a map of the grain boundary which can be used to position the probe in defined locations for spectroscopy. In the case of oxides, a structural model of the metal atom positions can be determined directly from the image. Furthermore, using a simple bond-valence sum minimization routine, the oxygen atoms can be placed so that the structure contains atoms that have valences consistent with their expected formal valence state.

Atomic and Electronic Structure Analysis of Σ=3, 9 and 27 Boundary, and Multiple Junction in β-SiC

1999 ◽  
Vol 589 ◽  
Author(s):  
K. Tanaka ◽  
M. Kohyama
Keyword(s):  
Electronic Structure ◽  
Energy Loss ◽  
Twin Boundary ◽  
Structural Unit ◽  
High Resolution Electron Microscopy ◽  
Coherent Twin Boundary ◽  
Atomic Structures ◽  
Resolution Electron ◽  
Electron Energy Loss ◽  
Atomic And Electronic Structure

AbstractThe atomic structures of σ=3, 9 and 27 boundaries, and multiple junctions in β-SiC were studied by high-resolution electron microscopy (HREM). Especially, the existence of the variety of structures of σ=3 incoherent twin boundaries and σ=27 boundary was shown by HREM. The structures of σ=3, 9 and 27 boundary were explained by structural unit models. Electron energy-loss spectroscopy (EELS) was used to investigate the electronic structure of grain boundaries. The spectra recorded from bulk, {111}σ=3 coherent twin boundary (CTB) and {1211}σ=3 incoherent twin boundary (ITB) did not show significant differences. Especially, the energy-loss corresponding to carbon 1s-to Φ* transition was not found. It indicates that C atoms exist at grain boundary on the similar condition of bulk

Structure of Frilled Carbon Nanowires Synthesized by Sulfur-assisted Chemical Vapor Deposition

2001 ◽  
Vol 706 ◽  
Author(s):  
Tadashi Mitsui ◽  
Takashi Sekiguchi ◽  
Mikka Nishitani-Gamo ◽  
Yafei Zhang ◽  
Toshihiro Ando
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Microwave Plasma ◽  
Chemical Vapor ◽  
Carbon Phase ◽  
Transmission Electron ◽  
Diamond Substrate ◽  
Thin Film Catalyst ◽  
Electron Energy Loss ◽  
Electron Energy Loss Spectra

AbstractEffects of hydrogen sulfide on the structure of carbon nanotubes (CNTs) were studied using high-resolution transmission electron microscopy (HRTEM) and electron energy loss spectroscopy (EELS). The CNTs were synthesized with an iron thin-film catalyst by microwave plasma-assisted CVD on the diamond substrate. The HRTEM images revealed that essentially all of the CNTs obtained in this study were multiwall (MWCNT). The addition of H2S resulted in nanotubes with split skins as cornhusks and/or frills. Electron energy loss spectra of the cornhusks indicated that they consist of sp2, sp3 and amorphous carbon phase. The spectra revealed that the sp3 to sp2 ratio at the points where cornhusks divide from the main stem was more than that at the edge of the cornhusks. No evidence of sulfur incorporation into the MWCNTs grown with the H2S addition was found. We speculate that the chemical nature of sulfur on the CNT growth yields such anomalous structure.

Low-loss Electron Energy-loss Spectroscopy and Dielectric Function of Biological and Geological Polymorphs of CaCO3

1999 ◽  
Vol 5 (5) ◽  
pp. 358-364 ◽  
Author(s):  
Kalpana S. Katti ◽  
Maoxu Qian ◽  
Daniel W. Frech ◽  
Mehmet Sarikaya
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Dielectric Function ◽  
Electronic Structures ◽  
Microstructural Characterization ◽  
Low Loss ◽  
Composite Microstructure ◽  
Abalone Shell ◽  
Electron Energy Loss ◽  
Electron Excitations

Previous work on microstructural characterization has shown variations in terms of defects and organization of nanostructures in the two polymorphs of calcium carbonate, calcite, and aragonite in mollusc shells. Large variations in mechanical properties are observed between these sections which have been attributed to variations in composite microstructure as well as intrinsic properties of the inorganic phases. Here we present local low-loss electron energy-loss spectroscopic (EELS) study of calcitic and aragonitic regions of abalone shell that were compared to geological (single-crystal) counterpart polymorphs to reveal intrinsic differences that could be related to organismal effects in biomineralization. In both sets of samples, local dielectric function is computed using Kramer-Kronig analysis. The electronic structures of biogenic and geological calcitic materials are not significantly different. On the other hand, electronic structure of biogenic aragonite is remarkably different from that of geological aragonite. This difference is attributed to the increased contribution from single electron excitations in biogenic aragonite as compared to that of geological aragonite. Implications of these changes are discussed in the context of macromolecular involvement in the making of the microstructures and properties in biogenic phases.

Carbon Onion Films-Molecular Interactions of Multi-Layer Fullerenes

2009 ◽  
Vol 1204 ◽  
Author(s):  
Raed A. Alduhaileb ◽  
Virginia M. Ayres ◽  
Benjamin W. Jacobs ◽  
Xudong Fan ◽  
Kaylee McElroy ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Energy Loss ◽  
Electron Energy ◽  
High Resolution Electron Microscopy ◽  
Synthesis Temperature ◽  
Carbon Onion ◽  
Resolution Electron ◽  
Electron Energy Loss ◽  
Electron Energy Loss Spectra ◽  
Scanning Electron

AbstractThe evolution of carbon onion structure from spherical to polyhedral is correlated with changes in the sp3/sp2 ratio as a function of increasing synthesis temperature using electron energy loss spectroscopy, scanning electron microscopy, and high resolution electron microscopy. Results that are obtained using asymmetric f-variance versus symmetric Gaussian deconvolution of electron energy loss spectra are compared. The possibility of a separate peak at 287 eV is discussed.

Nanoscale analysis of a Co-SrTiO3 interface in a Magnetic tunnel junction

2002 ◽  
Vol 746 ◽  
Author(s):  
J.-L. Maurice ◽  
F. Pailloux ◽  
D. Imhoff ◽  
J.-P. Contour ◽  
A. Barthélémy ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Energy Loss ◽  
Electron Energy ◽  
Tunnel Junction ◽  
Electron Energy Loss Spectroscopy ◽  
Magnetic Tunnel Junction ◽  
High Resolution Electron Microscopy ◽  
Resolution Electron ◽  
Electron Energy Loss

ABSTRACTWe use High Resolution Electron Microscopy together with Electron Energy Loss Spectroscopy to analyze the crystallography and the chemical configuration of a Co/SrTiO3 interface in a Co/SrTiO3/La2/3Sr1/3MnO3 magnetic tunnel junction.PACS: 75.47.-m, 75.70.Cn, 68.37.Lp, 79.20.Uv

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