Novel Technique to Produce Strongly Adherent Diamond Films on Fe- and Ni-Base Alloys

1995 ◽  
Vol 416 ◽  
Author(s):  
Othon R. Monteiro ◽  
Zhi Wang ◽  
Ian G. Brown
Keyword(s):  
Electron Microscopy ◽  
Diamond Films ◽  
Weak Links ◽  
Chemical Affinity ◽  
Materials Properties ◽  
Novel Technique ◽  
Intermediate Layers ◽  
Transmission Electron ◽  
Deposition Techniques ◽  
Selection Of

ABSTRACTAn evaluation of the use of intermediate layers for promoting adhesion between diamond and Fe and Ni base alloys is presented. The lack of adhesion between diamond and such alloys has prevented its use as a protective coating in applications at intermediate temperatures. In this study we use a combination of plasma assisted deposition techniques together with controlled bias of the substrate in order to deposit intermediate layers, and simultaneously achieve a thorough intermixing of the elements at the interface, in order to increase the adhesion between the layers. We have compared the performance of different carbide forming metals, as well as other materials. Properties considered in the selection of the appropriate intermediate layers are: chemical affinity with carbon, thermal expansion coefficient, mechanical properties, and adhesion to diamond and to the base metal as well. In the case of multiple layers, adhesion strength was measured after every new layer was deposited, in order to identify any weak links of the composite structure. Transmission electron microscopy was used to determine the microstructure and phases. An analysis is provided of the resulting performance on the basis of the microstructure.

Applications of Transmission Electron Microscopy in the Characterization of Metal Machinability

1968 ◽  
Vol 26 ◽  
pp. 442-443 ◽  
Author(s):  
L.E. Murr ◽  
A.B. Draper
Keyword(s):  
Electron Microscopy ◽  
State Physics ◽  
Test Material ◽  
Milling Machine ◽  
Rotary Table ◽  
Solid State Physics ◽  
Materials Properties ◽  
Transmission Electron ◽  
Selection Of

The industrial characterization of the machinability of metals and alloys has always been a very arbitrarily defined property, subject to the selection of various reference or test materials; and the adoption of rather naive and misleading interpretations and standards. However, it seems reasonable to assume that with the present state of knowledge of materials properties, and the current theories of solid state physics, more basic guidelines for machinability characterization might be established on the basis of the residual machined microstructures. This approach was originally pursued by Draper; and our presentation here will simply reflect an exposition and extension of this research.The technique consists initially in the production of machined chips of a desired test material on a horizontal milling machine with the workpiece (specimen) mounted on a rotary table vice. A single cut of a specified depth is taken from the workpiece (0.25 in. wide) each at a new tool location.

Selection and Preparation of Specific Tissue Regions For Tem Using Large Epoxy-Embedded Blocks

1973 ◽  
Vol 31 ◽  
pp. 324-325 ◽  
Author(s):  
P. M. Lowrie ◽  
W. S. Tyler
Keyword(s):  
Electron Microscopy ◽  
Anatomical Structures ◽  
Ultrastructural Studies ◽  
Transmission Electron ◽  
Microscopic Evaluation ◽  
Embedded Blocks ◽  
Specific Tissue ◽  
Definition Of ◽  
Areas Of Interest ◽  
Selection Of

The importance of examining stained 1 to 2μ plastic sections by light microscopy has long been recognized, both for increased definition of many histologic features and for selection of specimen samples to be used in ultrastructural studies. Selection of specimens with specific orien ation relative to anatomical structures becomes of critical importance in ultrastructural investigations of organs such as the lung. The uantity of blocks necessary to locate special areas of interest by random sampling is large, however, and the method is lacking in precision. Several methods have been described for selection of specific areas for electron microscopy using light microscopic evaluation of paraffin, epoxy-infiltrated, or epoxy-embedded large blocks from which thick sections were cut. Selected areas from these thick sections were subsequently removed and re-embedded or attached to blank precasted blocks and resectioned for transmission electron microscopy (TEM).

Preparation of Ceramic Particulates for Transmission Electron Microscopy

1980 ◽  
Vol 38 ◽  
pp. 196-197
Author(s):  
R. J. Lauf ◽  
H. Keating
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ceramic Materials ◽  
Ion Milling ◽  
Plastic Films ◽  
Transmission Electron ◽  
Specimen Orientation ◽  
Selection Of

The preparation of fragmented or particulate ceramic materials for transmission electron microscopy (TEM) examination has traditionally been difficult, particularly if a durable, permanent specimen is desired. Furthermore, most established methods for dealing with micron- and submicron-sized samples (e.g., dispersion in plastic films) do not permit selection of orientations or ion thinning. A technique has been developed that is useful for a variety of materials, permits the selection of specimen orientation, is compatible with ion milling requirements, and produces a durable specimen that can be reexamined later if necessary.

Defects Analysis of Diamond Films in Cross Section Using Cathodoluminescence and High-Resolution Transmission Electron Microscopy

2001 ◽  
Vol 78-79 ◽  
pp. 197-204
Author(s):  
Daisuke Takeuchi ◽  
Hideyuki Watanabe ◽  
Sadanori Yamanaka ◽  
Hidetaka Sawada ◽  
Hideki Ichinose ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Cross Section ◽  
Diamond Films ◽  
Transmission Electron ◽  
Defects Analysis

scholarly journals A novel technique to synthesis of tenorite (CuO) nanoparticles from low concentration CuSO4 solution

2011 ◽  
Vol 47 (1) ◽  
pp. 73-78 ◽  
Author(s):  
E. Darezereshki ◽  
F. Bakhtiari
Keyword(s):  
Electron Microscopy ◽  
Decomposition Method ◽  
Raw Materials ◽  
Spherical Shape ◽  
Cuo Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thermal Decomposition Method ◽  
Novel Technique ◽  
Transmission Electron

In this study CuO nanoparticles were prepared via direct thermal decomposition method using basic copper sulphates as wet chemically synthesized precursor which was calcined in air at 750?C for 2h. Samples were characterized by thermogravimetric (TG-DSC), X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), infrared spectrum (IR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The XRD, EDS, and IR results indicated that the synthesized CuO particles were pure. The SEM and TEM results showed that the CuO nanoparticles were of approximate spherical shape, and 170?5 nm in size. Using this method, Cuo nanoparticles could be produced without using organic solvent, expensive raw materials, and complicated equipment.

A Study of the Origin of Band-A Emission in Homoepitaxial Diamond Thin Films

1999 ◽  
Vol 588 ◽  
Author(s):  
Daisuke Takeuchi ◽  
Hideyuki Watanabe ◽  
Sadanori Yamanaka ◽  
Hideyo Okushi ◽  
Koji Kajimura ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Grain Boundaries ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Plasma Chemical Vapor Deposition ◽  
Transmission Electron ◽  
Excitonic Emission

AbstractThe band-A emission (around 2.8 eV) observed in high quality (device-grade) homoepitaxial diamond films grown by microwave-plasma chemical vapor deposition (CVD) was studied by means of scanning cathodoluminescence spectroscopy and high-resolution transmission electron microscopy. Recent progress in our study on homoepitaxial diamond films was obtained through the low CH4/H2 conditions by CVD. These showed atomically flat surfaces and the excitonic emission at room temperature, while the band-A emission (2.95 eV) decreased. Using these samples, we found that the band-A emission only appeared at unepitaxial crystallites (UC) sites, while other flat surface parts still showed the excitonic emission. High-resolution transmission electron microscopy revealed that there were grain boundaries which contained π-bonds in UC. This indicates that one of the origin of the band-A emission in diamond films is attributed to π bonds of grain boundaries.

Intra- and Intergranular Fracture of Diamond Thin Films

1989 ◽  
Vol 162 ◽  
Author(s):  
H. A. Hoff ◽  
A. A. Morrish ◽  
W. A. Carrington ◽  
J. E. Butler ◽  
B. B. Rath
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Relative Strength ◽  
Ambient Atmosphere ◽  
Transmission Electron ◽  
Welding Torch ◽  
Diamond Thin Films ◽  
Inherent Strength

ABSTRACTDiamond thin films have been synthesized at low pressures by chemical vapor deposition (CVD) and, recently, at ambient atmosphere with an oxygen-acetylene welding torch. By the application of appropriate thermal or mechanical stresses to the substrate, the diamond films can be delaminated. The delaminated films which are only a few microns thick have been fractured by manual bending. Scanning electron microscopy (SEM) examination of fractured CVD diamond films shows the presence of primarily intragranular fracture attesting to the inherent strength of the films. Using transmission electron microscopy (TEM), twinning and stacking faults are seen within the crystallites of the films along the fracture surfaces. By combining SEM and TEM examination, the relative degree of intragranular fracture found in films synthesized by both CVD and oxygen-acetylene torch has been investigated. Possible mechanisms for the intragranular fracture and the relative strength of such films are discussed.

Fabrication of Multi-Level Buried Oxide Layers by Oxygen-Ion-Implantation into Si/Ge multilayers

1996 ◽  
Vol 438 ◽  
Author(s):  
Toshio Ogino ◽  
Yoshihiro Kobayashi ◽  
Kuniyil Prabhakaran ◽  
Koji sumitomo
Keyword(s):  
Electron Microscopy ◽  
Silicon Dioxide ◽  
Multilayered Structures ◽  
Oxide Layers ◽  
Oxygen Ions ◽  
Novel Technique ◽  
Oxygen Ion ◽  
Transmission Electron ◽  
Multi Level ◽  
Oxygen Ion Implantation

AbstractWe propose a novel technique based on preferential oxidation of Si in the Si/Ge system. Oxygen ions were implanted at 30 keV into Si/Ge multilayers while the substrate temperature was kept below 100°C. Significant oxygen concentration was then observed at the Si/Ge interfaces and at a thin Si layer embedded into the Ge layer. When the samples were then annealed above 400°c, the bonding state of the Si oxide approached that of SiO2. During this process, Ge atoms were expelled from the oxide layers. Transmission electron microscopy confirmed that silicon dioxide layers were formed. This new technique can be used to form semiconductor/insulator multilayered structures from Si/Ge multilayers.

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