Detection of iron-oxide layer on the surface of iron nitride using high-resolution electron microscopy and Fourier filtering

2004 ◽  
Vol 53 (2) ◽  
pp. 143-148 ◽  
Author(s):  
Z.-Q. Liu
Keyword(s):  
Electron Microscopy ◽  
Iron Oxide ◽  
High Resolution ◽  
Oxide Layer ◽  
High Resolution Electron Microscopy ◽  
Iron Nitride ◽  
Resolution Electron ◽  
Fourier Filtering

Structure of twinned {113} defects in high-dose oxygen implanted silicon-on-insulator material

1991 ◽  
Vol 6 (4) ◽  
pp. 792-795 ◽  
Author(s):  
Supapan Visitserngtrakul ◽  
Stephen J. Krause ◽  
John C. Barry
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Oxide Layer ◽  
High Resolution Electron Microscopy ◽  
Silicon On Insulator ◽  
High Dose ◽  
Diamond Structure ◽  
Bulk Silicon ◽  
Coherent Interface ◽  
Resolution Electron

Conventional and high resolution electron microscopy (HREM) were used to study the structure of {113} defects in high-dose oxygen implanted silicon. The defects are created with a density of 1011 cm−2 below the buried oxide layer in the substrate region. The HREM images of the {113} defects are similar to the ribbon-like defects in bulk silicon. It is proposed that there is a third possible structure of the defects, in addition to coesite and/or hexagonal structures. Portions of some defects exhibit the original cubic diamond structure which is twinned across {115} planes. The atomic model shows that the {115} interface is a coherent interface with alternating five- and seven-membered rings and no dangling bonds.

Twinning Structure of {113} Defects in High-Dose Oxygen Implanted Silicon-on-Insulator Material.

1989 ◽  
Vol 163 ◽  
Author(s):  
S. Visitserngtrakul ◽  
J. Barry ◽  
S. Krause
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Oxide Layer ◽  
High Resolution Electron Microscopy ◽  
Silicon On Insulator ◽  
High Dose ◽  
Diamond Structure ◽  
Bulk Silicon ◽  
Coherent Interface ◽  
Resolution Electron

AbstractConventional and high resolution electron microscopy (HREM) were used to study the structure of the {113} defects in high-dose oxygen implanted silicon. The defects are created with a density of 1011 cm-2 below the buried oxide layer in the substrate region. The {113} defects are similar to the ribbon-like defects in bulk silicon. Our HREM observations show that two crystalline phases are present in the defect. Portions of the defects exhibit the original cubic diamond structure which is twinned across {115} planes. The atomic model shows that the {115} interface is a coherent interface with alternating five- and seven-membered rings and no dangling bonds.

Comparative Oxidation Studies of Polycrystalline HP and CVD Silicon Carbides by TEM

1991 ◽  
Vol 49 ◽  
pp. 938-939
Author(s):  
J.S. Bow ◽  
M.J. Kim ◽  
R.W. Carpenter
Keyword(s):  
Electron Microscopy ◽  
High Temperature ◽  
Reaction Time ◽  
High Resolution ◽  
Oxide Layer ◽  
Crystalline Phase ◽  
High Resolution Electron Microscopy ◽  
Substrate Type ◽  
Resolution Electron ◽  
Silicon Carbides

The excellent oxidation resistance of SiC at high temperature results from formation of a protective SiO2 layer in a strongly oxidizing environment. The oxide layer is often initially amorphous, may transform to a crystalline phase for extended reaction time, especially crystobalite above 1200°C. Our objective is use of high resolution electron microscopy methods to determine the oxide layer microstructure dependence on SiC substrate type, and especially to investigate existence of an intermediate Si-O-C phase between the oxide layer and substrate.

Experimental and computed HREM images of the structure and defects in gadolinium silicate

1982 ◽  
Vol 15 (2) ◽  
pp. 211-215
Author(s):  
H.-U. Nissen ◽  
A. Kumao ◽  
J. Ylä-Jääski ◽  
R. Wessicken
Keyword(s):  
Electron Microscopy ◽  
Electron Beam ◽  
Rare Earth ◽  
High Resolution ◽  
High Resolution Electron Microscopy ◽  
Image Contrast ◽  
Zone Axis ◽  
Resolution Electron ◽  
Fourier Filtering ◽  
Image Fit

Monoclinic Gd2SiO5 has been investigated by high-resolution electron microscopy (HREM) at 100 kV. Structure images are observed in the [100] and [001] projections and calculations of the image contrast using the multislice approximation are carried out to interpret the observations. For thin samples the image fit is improved by Fourier filtering of the observed images. For thicker samples the fit is found to be very sensitive to small tilt deviations of the zone axis to the electron beam. For defects observed in a fast-cooled specimen, a model in which Gd atoms replace Si atoms in segments along the (100) plane is proposed and tested by contrast calculations. These defects may be one of the reasons for deviations from stoichiometry as frequently observed in rare-earth silicates.

High Resolution Electron Microscopy of Defects in High-Dose Oxygen Implanted Silicon-On-Insulator Material

1990 ◽  
Vol 183 ◽  
Author(s):  
S. Visitserngtrakul ◽  
C. O. Jung ◽  
B. F. Cordts ◽  
P. Roitman ◽  
S. J. Krause
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Oxide Layer ◽  
Stacking Faults ◽  
High Resolution Electron Microscopy ◽  
Silicon On Insulator ◽  
High Dose ◽  
Wafer Temperature ◽  
Buried Oxide ◽  
Resolution Electron

AbstractHigh resolution electron microscopy (HREM) has been used to study the atomic arrangement of defects formed during high-dose oxygen implantation of silicon-on-insulator material. The effect of implantation parameters of wafer temperature, dose, and current density were investigated. Wafer temperature had the largest effect on the type and character of the defects. Above the buried oxide layer in the top silicon layer, HREM revealed that microtwins and stacking faults were created during implantation from 350–450°C. From 450–550°C, stacking faults were longer and microtwinning was reduced. From 550–700°C, a new type of defect was observed which had lengths of 40 to 140 nm and consisted of several discontinuous stacking faults which were randomly spaced and separated by two to eight atomic layers. We have referred to them as “multiply faulted defects” (MFDs). Beneath the buried oxide layer in the substrate region, the defects observed included stacking faults and ( 113 ) defects. The results indicated that some parts of the ( 1131 defects can assume a cubic diamond structure created through a twin operation across (115) planes. Details of the structure and formation mechanisms of MFDs and other defects will be discussed.

Structural analysis of the surface-layer protein of spirillum serpens by high-resolution electron microscopy

1983 ◽  
Vol 41 ◽  
pp. 738-739
Author(s):  
W. H. Wu ◽  
R. M. Glaeser
Keyword(s):  
Electron Microscopy ◽  
Surface Layer ◽  
Structural Analysis ◽  
High Resolution ◽  
Low Dose ◽  
High Resolution Electron Microscopy ◽  
Optical Diffraction ◽  
Surface Layer Protein ◽  
Morphological Unit ◽  
Resolution Electron

Spirillum serpens possesses a surface layer protein which exhibits a regular hexagonal packing of the morphological subunits. A morphological model of the structure of the protein has been proposed at a resolution of about 25 Å, in which the morphological unit might be described as having the appearance of a flared-out, hollow cylinder with six ÅspokesÅ at the flared end. In order to understand the detailed association of the macromolecules, it is necessary to do a high resolution structural analysis. Large, single layered arrays of the surface layer protein have been obtained for this purpose by means of extensive heating in high CaCl2, a procedure derived from that of Buckmire and Murray. Low dose, low temperature electron microscopy has been applied to the large arrays.As a first step, the samples were negatively stained with neutralized phosphotungstic acid, and the specimens were imaged at 40,000 magnification by use of a high resolution cold stage on a JE0L 100B. Low dose images were recorded with exposures of 7-9 electrons/Å2. The micrographs obtained (Fig. 1) were examined by use of optical diffraction (Fig. 2) to tell what areas were especially well ordered.

Electron microscopy of rabbit FC crystals

1983 ◽  
Vol 41 ◽  
pp. 730-731
Author(s):  
Robert A. Grant ◽  
Laura L. Degn ◽  
Wah Chiu ◽  
John Robinson
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
High Resolution Electron Microscopy ◽  
Molecular Replacement ◽  
X Ray ◽  
X Ray Crystallography ◽  
Resolution Electron ◽  
Replacement Technique ◽  
Hydrated Crystal ◽  
Molecular Structure Analysis

Proteolytic digestion of the immunoglobulin IgG with papain cleaves the molecule into an antigen binding fragment, Fab, and a compliment binding fragment, Fc. Structures of intact immunoglobulin, Fab and Fc from various sources have been solved by X-ray crystallography. Rabbit Fc can be crystallized as thin platelets suitable for high resolution electron microscopy. The structure of rabbit Fc can be expected to be similar to the known structure of human Fc, making it an ideal specimen for comparing the X-ray and electron crystallographic techniques and for the application of the molecular replacement technique to electron crystallography. Thin protein crystals embedded in ice diffract to high resolution. A low resolution image of a frozen, hydrated crystal can be expected to have a better contrast than a glucose embedded crystal due to the larger density difference between protein and ice compared to protein and glucose. For these reasons we are using an ice embedding technique to prepare the rabbit Fc crystals for molecular structure analysis by electron microscopy.

High resolution electron microscopy of lanthanum phosphate crystals

1978 ◽  
Vol 36 (1) ◽  
pp. 274-275
Author(s):  
J. C. Wheatley ◽  
J. M. Cowley
Keyword(s):  
Electron Microscopy ◽  
Catalytic Activity ◽  
High Resolution ◽  
Petroleum Industry ◽  
High Resolution Electron Microscopy ◽  
Lanthanum Phosphate ◽  
Good Catalyst ◽  
Resolution Electron ◽  
Good Catalytic Activity ◽  
Physical And Chemical

Rare-earth phosphates are of particular interest because of their catalytic properties associated with the hydrolysis of many aromatic chlorides in the petroleum industry. Lanthanum phosphates (LaPO4) which have been doped with small amounts of copper have shown increased catalytic activity (1). However the physical and chemical characteristics of the samples leading to good catalytic activity are not known.Many catalysts are amorphous and thus do not easily lend themselves to methods of investigation which would include electron microscopy. However, the LaPO4, crystals are quite suitable samples for high resolution techniques.The samples used were obtained from William L. Kehl of Gulf Research and Development Company. The electron microscopy was carried out on a JEOL JEM-100B which had been modified for high resolution microscopy (2). Standard high resolution techniques were employed. Three different sample types were observed: 669A-1-5-7 (poor catalyst), H-L-2 (good catalyst) and 27-011 (good catalyst).

Possible applications of fraunhofer holography in high resolution electron microscopy

1978 ◽  
Vol 36 (1) ◽  
pp. 222-223 ◽  
Author(s):  
N. Bonnet ◽  
M. Troyon ◽  
P. Gallion
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Transfer Function ◽  
Radiation Damage ◽  
High Resolution Electron Microscopy ◽  
Far Field ◽  
Field Region ◽  
Crystalline Materials ◽  
Resolution Electron ◽  
The Ideal

Two main problems in high resolution electron microscopy are first, the existence of gaps in the transfer function, and then the difficulty to find complex amplitude of the diffracted wawe from registered intensity. The solution of this second problem is in most cases only intended by the realization of several micrographs in different conditions (defocusing distance, illuminating angle, complementary objective apertures…) which can lead to severe problems of contamination or radiation damage for certain specimens.Fraunhofer holography can in principle solve both problems stated above (1,2). The microscope objective is strongly defocused (far-field region) so that the two diffracted beams do not interfere. The ideal transfer function after reconstruction is then unity and the twin image do not overlap on the reconstructed one.We show some applications of the method and results of preliminary tests.Possible application to the study of cavitiesSmall voids (or gas-filled bubbles) created by irradiation in crystalline materials can be observed near the Scherzer focus, but it is then difficult to extract other informations than the approximated size.

Sign in / Sign up

Export Citation Format

Share Document