Atomic and Electronic Structure of Boron-Doped Diamond Grain Boundaries Studied by Arhvtem and ab-Initio Calculation

2003 ◽  
Vol 764 ◽  
Author(s):  
Hiroyuki Togawa ◽  
Hideki Ichinose
Keyword(s):  
Ab Initio ◽  
Grain Boundaries ◽  
Ab Initio Calculation ◽  
Structure Model ◽  
Boron Doped Diamond ◽  
Boron Doped ◽  
Transmission Electron ◽  
Diamond Grain ◽  
Electron Energy Loss ◽  
Atomic And Electronic Structure

AbstractAtomic resolution high-voltage transmission electron microscopy and electron energy loss spectroscopy were performed on grain boundaries of boron-doped diamond, cooperated with the ab-initio calculation. Segregated boron in the {112}∑3 boundary was caught by the EELS spectra. The change in atomic structure of the segregated boundary was successfully observed from the image by ARHVTEM. Based on the ARHVTEM image, a segregted structure model was proposed.

Structure and Stability of Grain Boundaries in Molybdenum with Segregated Carbon Impurities

1999 ◽  
Vol 578 ◽  
Author(s):  
R. Janisch ◽  
T. Ochs ◽  
A. Merkle ◽  
C. Elsässer
Keyword(s):  
Ab Initio ◽  
Grain Boundaries ◽  
Density Functional ◽  
Local Density ◽  
Structural Parameters ◽  
Carbide Phases ◽  
Carbon Impurities ◽  
Transmission Electron ◽  
Local Density Functional Theory ◽  
Symmetrical Tilt

AbstractThe segregation of interstitial impurities to symmetrical tilt grain boundaries (STGB) in bodycentered cubic transition metals is studied by means of ab-initio electronic-structure calculations based on the local density functional theory (LDFT). Segregation energies as well as changes in atomic and electronic structures at the ΣE5 (310) [001] STGB in Mo caused by segregated interstitial C atoms are investigated. The results are compared to LDFT data obtained previously for the pure Σ5 (310) [001] STGB in Mo. Energetic stabilities and structural parameters calculated ab initio for several crystalline Molybdenum Carbide phases with cubic, tetragonal or hexagonal symmetries and different compositions, MoCx, are reported and compared to recent high-resolution transmission electron microscopy (HRTEM) observations of MoCx, intergranular films and precipitates formed by C segregation to a Σ5 (310) [001] STGB in a Mo bicrystal.

Atomie and Electron Structure of Diamond Grain boundaries in a Polycrystalline Film

1997 ◽  
Vol 472 ◽  
Author(s):  
Hideki Ichinose ◽  
Megumi Nakanose ◽  
Yaogan Zhang
Keyword(s):  
Grain Boundaries ◽  
Polycrystalline Diamond ◽  
High Resolution Electron Microscopy ◽  
Electron Structure ◽  
Polished Surface ◽  
Resolution Electron ◽  
Diamond Grain ◽  
Electron Energy Loss ◽  
Π State ◽  
Polycrystalline Diamond Film

AbstractA polycrystalline diamond film was grown on the polished surface of silicon substrate in H2-CO-O2 mixing gas. Atomic and electron structure of grain boundaries in the film was investigated by both high resolution electron microscopy and electron energy loss spectroscopy. CSL boundaries in the film showed characteristic feature in atomic structure; Σ 9 CSL boundary was parallel not to (221) plane but to (114) plane. A new line which correspond to π * state was found in addition to major σ * line in the EELS spectra of the boundary which contained three coordinate atoms. Observed π * line shows occurred change of a dangling bond (pz electron) to π state. No π * line appeared in the EELS spectra obtained from boundaries which contained no three coordinate atom such as (111) Σ 3 boundary.

scholarly journals Quantitative In-Situ Nanoindentation of Thin Films in a Transmission Electron Microscope

2001 ◽  
Vol 7 (S2) ◽  
pp. 912-913
Author(s):  
A.M. Minorl ◽  
E.A. Stach ◽  
J.W. Morris
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Real Time ◽  
Silicon Substrates ◽  
Boron Doped Diamond ◽  
Boron Doped ◽  
Transmission Electron ◽  
Diamond Indenter ◽  
Force Calibration

A unique in situ nanoindentation stage has been built and developed at the National Center for Electron Microscopy in Berkeley, CA. By using piezoceramic actuators to finely position a 3-sided, boron-doped diamond indenter, we are able to image in real time the nanoindentation induced deformation of thin films. Recent work has included the force-calibration of the indenter, using silicon cantilevers to establish a relationship between the voltage applied to the piezoactuators, the displacement of the diamond tip, and the force generated.In this work, we present real time, in situ TEM observations of the plastic deformation of Al thin films grown on top of lithographically-prepared silicon substrates. The in situ nanoindentations require a unique sample geometry (see Figure 1) in which the indenter approaches the specimen normal to the electron beam. in order to meet this requirement, special wedge-shaped silicon samples were designed and microfabricated so that the tip of the wedge is sharp enough to be electron transparent.

AB initio calculation of the atomic and electronic structure for Sb adsorbed on GaAs(110)

1993 ◽  
Vol 43 (9-10) ◽  
pp. 1003-1007 ◽  
Author(s):  
Wolf Gero Schmidt ◽  
Bernd Wenzien ◽  
Friedhelm Bechstedt
Keyword(s):  
Electronic Structure ◽  
Ab Initio ◽  
Ab Initio Calculation ◽  
Atomic And Electronic Structure

Effect of growth conditions on B-doped carbon nanotubes

2006 ◽  
Vol 21 (12) ◽  
pp. 3058-3064 ◽  
Author(s):  
Sara M.C. Vieira ◽  
Odile Stéphan ◽  
David L. Carroll
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Arc Discharge ◽  
Amorphous Material ◽  
Graphite Powder ◽  
Growth Conditions ◽  
Multiwalled Carbon ◽  
Boron Doped ◽  
Transmission Electron ◽  
Electron Energy Loss

The modified arc-discharge technique was used for the growth of boron-doped multiwalled carbon nanotubes. A variety of weight percentages of boron and sulfur were mixed (0.5–15 wt%) with graphite powder and packed in the consumable anode. Transmission electron microscopy, Raman spectroscopy, thermogravimetric analysis (TGA), and electron energy loss spectroscopy (EELS) were used to characterize the samples. EELS indicated a small percentage of boron present (<1 at.%) in the nanotubes. Sulfur was used primarily to enhance boron incorporation; however, Raman and TGA measurements indicated fewer defects and/or amorphous material present when sulfur was added.

scholarly journals Atomic and Electronic Structure of Diamond Grain Boundaries

Materia Japan ◽  
1998 ◽  
Vol 37 (12) ◽  
pp. 1007-1007
Author(s):  
Hideki Ichinose ◽  
Megumi Nakanose
Keyword(s):  
Electronic Structure ◽  
Grain Boundaries ◽  
Diamond Grain ◽  
Atomic And Electronic Structure

Evidence for an Abrupt Transition between SiO2 and SiC from EELS and Ab Initio Modelling

2019 ◽  
Vol 963 ◽  
pp. 199-203 ◽  
Author(s):  
Jonathon Cottom ◽  
Manesh V. Mistry ◽  
Gernot Gruber ◽  
Gregor Pobegen ◽  
Thomas Aichinger ◽  
...  
Keyword(s):  
Energy Loss ◽  
Ab Initio ◽  
Electron Energy Loss Spectroscopy ◽  
Ab Initio Calculation ◽  
Interface Morphology ◽  
Gate Oxides ◽  
Abrupt Transition ◽  
Ab Initio Simulations ◽  
Carbon Excess ◽  
Electron Energy Loss

Electron energy loss spectroscopy (EELS) and ab initio simulations are combined in this study to produce an atomistic interpretation of the interface morphology in lateral 4H-SiC / SiO2 MOSFETs with deposited gate oxides. This allows the question of interface abruptness, and the presence the postulated SiOxCy interlayer to be explored for a subset of devices with deposited oxides. From comparison between EELS and ab initio calculation the interfaces considered are best described as abrupt, but stepped, transitioning without any of the carbon excess or SiOxCy interlayer that have been described for other devices observed.

Growth of Device-Quality Homoepitaxial Diamond Thin Films

1989 ◽  
Vol 162 ◽  
Author(s):  
M. W. Geis
Keyword(s):  
Activation Energy ◽  
Growth Conditions ◽  
Device Fabrication ◽  
Diamond Growth ◽  
High Resistivity ◽  
Boron Doped Diamond ◽  
Boron Doped ◽  
Transmission Electron ◽  
Heavily Doped ◽  
P Type

ABSTRACTDiamond has an electric-field breakdown 20 times that of Si and GaAs, and a saturated velocity twice that of Si. This results in a predicted cut off frequency for high-power diamond transistors 40 times that of similar devices made of Si or GaAs. Boron is the only known impurity that can be used to lightly dope diamond. This p-type dopant has an activation energy of 0.3 to 0.4 eV, which results in high-resistivity material that is undesirable for devices. However, heavily boron doped diamond has a very small activation energy and a low resistivity and is of device quality. Transistors can be designed that use only undoped and heavily doped diamond. One of the steps in a device fabrication sequence is homoepitaxial diamond growth. Lightly and heavily doped homoepitaxial diamond films were characterized by scanning and transmission electron microscopy, x-ray diffraction, measurements of resistivity as a function of temperature, and secondary ion mass spectroscopy. It was found that under appropriate growth conditions these films are of device quality.

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