Interfaces in Structural Ceramics

MRS Bulletin ◽  
1990 ◽  
Vol 15 (10) ◽  
pp. 51-59 ◽  
Author(s):  
M. Grant Norton ◽  
C. Barry Carter
Keyword(s):  
Structural Ceramics ◽  
Interface Engineering ◽  
Micro Structure ◽  
Complete Understanding ◽  
Intimate Contact ◽  
Transmission Electron ◽  
Processed Material ◽  
Wide Range ◽  
Alternative Materials ◽  
The Relationship

Structural ceramics are necessarily polycrystalline and their usefulness is largely determined by the interfaces between the grains. The relationship between the structure and chemistry of different interfaces and the micro-structure can be illustrated by reviewing studies of interfaces in a wide range of materials including such classical ceramics as Al2O3, the current “hightech” polyphase ceramics exemplified by ZrO2-toughened Al2O3, and the composite materials of the future. Using transmission electron microscopy is essential for a complete understanding, but limitations to its use must be recognized. Only by understanding the factors that control the behavior of these interfaces will it become possible to further extend the application of interface engineering.Structural ceramics are a group of materials that can be used for applications requiring their strength to persist at high temperatures or in conditions that would be particularly corrosive to alternative materials, which are usually metallic. Strength and strength-related properties such as toughness depend largely on the microstructural features of the processed material.The microstructure is defined by the morphology and size of the grains and the interfaces between these grains. If the grains are in intimate contact, then the interface is a grain boundary of the type familiar from studies of metals.

Microstructure of Gold Films Grown by Ion Induced Deposition

1987 ◽  
Vol 101 ◽  
Author(s):  
J.S. Ro ◽  
A.D. Dubner ◽  
C.V. Thompson ◽  
J. Melngailis
Keyword(s):  
Room Temperature ◽  
Growth Conditions ◽  
Micro Structure ◽  
Adsorbed Gas ◽  
Material Deposition ◽  
Transmission Electron ◽  
Deposition Yield ◽  
Gas Molecules ◽  
The Relationship ◽  
Substrate Temperatures

ABSTRACTA beam of ions incident on a substrate can cause adsorbed gas molecules to break up, resulting in material deposition. We have previously demonstrated deposition of gold from a gas of dimethyl gold hexafluoro acetylacetonate (C7H7F6O2Au) using both focused and broad ion beams. Here we investigate growth at various substrate temperatures and examine micro-structure using transmission electron microscopy. Films grown at room temperature were discontinuous even up to the thickness of 250μπι while films grown at higher substrate temperatures were continuous even at lower thicknesses. Deposition carried out on substrates at 100°C and 160°C using 70 kev Ar+ ions resulted in resistivities approaching the bulk value and a deposition yield of 60 to 75 atoms/ion. The relationship between growth conditions, micro-structure and resistivity will be discussed.

Intra- and submembrane particle densities during CO2 stimulation of H+ secretion in turtle bladder

1997 ◽  
Vol 272 (4) ◽  
pp. F491-F497 ◽  
Author(s):  
O. F. Kohn ◽  
A. R. Hand ◽  
P. P. Mitchell ◽  
P. R. Steinmetz
Keyword(s):  
Electron Microscopy ◽  
Apical Cell ◽  
Freeze Fracture ◽  
Alpha Cells ◽  
Transmission Electron ◽  
Wide Range ◽  
Freeze Fracture Electron Microscopy ◽  
The One ◽  
Apical Membranes ◽  
The Relationship

The apical cell membranes of the H+ secreting, alpha-intercalated cells of turtle urinary bladder (TB) are characterized by studs (cytoplasmic domains of V-adenosinetriphosphatase) on thin-section transmission electron microscopy and by intramembrane particles (spherical units, SPUs) occurring as rod-shaped particles on freeze-fracture electron microscopy. To examine the relationship between studs and SPUs, morphometric studies were carried out on bladders maintained in 5% CO2 and in the absence of exogenous CO2. The stud density per square micrometer of apical membrane was 3,909 +/” 352 (+/”SE) in four TBs (29 alpha-cells) at 5% CO2 and 3,667 +/” 448 (+/”SE) in the paired halves of the same bladders without CO2 (25 alpha-cells). Corresponding densities of SPUs counted on apical membranes of the same bladders (n = 4) were 3,941 +/” 545 in 5% CO2 and 3,599 +/” 511 without CO2. The similarity of the densities of studs and SPUs under both conditions indicates that each SPU within the membrane is matched by one stud projecting into the cytoplasm. The one-for-one relationship between studs and SPUs was preserved over a wide range of transport rates. Addition of CO2 caused only inconsistent increments in the densities of studs and SPUs despite substantial increases in H+ transport rate. Slight variations in spacing of studs were consistent with patterns of distribution of SPUs on fracture surfaces.

scholarly journals Effect of Alloying Additions on Microstructure, Mechanical and Magnetic Properties of Rapidly Cooled Bulk Fe-B-M-Cu (M = Ti, Mo and Mn) Alloys

2021 ◽  
Author(s):  
Mariusz Hasiak ◽  
Marzena Tkaczyk ◽  
Amadeusz Łaszcz ◽  
Jacek Olszewski
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Magnetic Properties ◽  
Elastic Modulus ◽  
Instrumented Indentation ◽  
Soft Magnetic ◽  
Alloying Additions ◽  
Transmission Electron ◽  
Wide Range ◽  
The Relationship

AbstractThe influence of alloying additions on the microstructure, mechanical, and magnetic properties of bulk Fe79B20Cu1, Fe79B16Ti4Cu1, Fe79B16Mo4Cu1 and Fe79B16Mn4Cu1 (at. pct) alloys was investigated. Nanocrystalline samples in the form of 3 mm rods were prepared directly by suction casting without additional heat treatment. Mössbauer spectroscopy, transmission electron microscopy and scanning electron microscopy studies confirmed that the investigated alloys consist α-Fe and Fe2B nanograins embedded in an amorphous matrix. The addition of alloying elements, such as Ti, Mo and Mn to Fe79B20Cu1 alloy increases the amount of amorphous phase and decreases the presence of Fe2B phase in all examined alloys. The mechanical properties of the samples, such as hardness, elastic modulus, and elastic energy ratio, were analysed by an instrumented indentation technique performed on a 12 × 12 nanoindentation grid. These tests allowed to characterise the mechanical properties of the regions observed in the same material. For the Fe79B20Cu1 alloy, the hardness of 1508 and 1999 HV, as well as Young’s modulus of 287 and 308 GPa, were estimated for the amorphous- and nanocrystalline-rich phase, respectively. The addition of Ti, Mo, and Mn atoms leads to a decrease in both hardness and elastic modulus for all regions in the investigated samples. Investigations of thermomagnetic characteristics show the soft magnetic properties of the studied materials. More detailed studies of magnetisation versus magnetic field curves for the Fe79B20−xMxCu1 (where x = 0 or 4; M = Ti, Mo, Mn) alloy, recorded in a wide range of temperatures, followed by the law of approach to magnetic saturation revealed the relationship between microstructure and magneto-mechanical properties.

Structure and Characteristics of Spherical-Pore Silicon Carbide

2011 ◽  
Vol 492 ◽  
pp. 142-145
Author(s):  
Qiang Li ◽  
You Jun Zheng ◽  
Jin Feng Xia ◽  
Dan Yu Jiang ◽  
Hao Wu ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Grain Structure ◽  
Structure And Properties ◽  
Micro Structure ◽  
Excellent Performance ◽  
Spherical Pore ◽  
Fine Grain ◽  
Wide Range ◽  
The Relationship ◽  
Sintered Silicon

Sintered Silicon Carbide material with fine grain structure shows excellent wear resistance, highly chemically resistance, excellent performance in a wide range of applications. This material can improve upon the exceptional corrosion and erosion resisting properties through the addition of unique micro pores. A designed spherical-pore Silicon Carbide material was obtained after pressureless sintering. The photomicrograph shows a typical appearance of unique micro pore. SEM was also employed to investigate the micro-structure of as-prepared SiC material. The properties of micro-pore Silicon Carbide, such as density, hardness, strength, etc. were determined in detail. The relationship between the spherical-pore structure and properties of Silicon Carbide were discussed.

Friction Stir Processing Multi-Run Modification of Cast Aluminum Alloy

2014 ◽  
Vol 611-612 ◽  
pp. 1595-1600 ◽  
Author(s):  
Marek Stanisław Węglowski ◽  
Mateusz Kopyściański ◽  
Stanisław Dymek
Keyword(s):  
Aluminum Alloy ◽  
Second Phase ◽  
Cast Aluminum Alloy ◽  
Cast Aluminum ◽  
Friction Stir ◽  
Transmission Electron ◽  
Processed Material ◽  
Second Phase Particles ◽  
The Relationship ◽  
Cast Condition

The effect of multi-run FSP modification of cast aluminum alloy AlSi9Mg are presented. The relationship between the number of trials and microstructures are shown. FSP process was performed on the typical milling machine specifically adopted for the processing trials. The microstructure was examined by light as well as scanning and transmission electron microscopy. The studies have shown that the multi-run FSP process causes decrease of the grain size and increase of the homogeneity of the microstructure. In contrast to the cast condition, the microstructure in the processed material was characterized by a relatively uniform distribution of the second phase particles. The size and aspect ratio of these particles decreased significantly. Application of FSP process resulted in a decrease of the porosity in the modified material. The modified materials achieved at perpendicular runs can be characterized by the higher dislocation density that obtained at parallel ones. The multi-run FSP process caused increase the elongation and ultimate tensile strength of modified material in comparison to properties of the cast aluminum alloy.

Comparison of Deterministic and Linear Cosine Spatial Filtering of Transmission Electron Micrographs

1972 ◽  
Vol 30 ◽  
pp. 596-597
Author(s):  
David A. Ansley
Keyword(s):  
Spherical Aberration ◽  
Focal Length ◽  
Chromatic Aberration ◽  
Spatial Filter ◽  
Operating Conditions ◽  
Objective Lens ◽  
List Type ◽  
Spatial Filters ◽  
Transmission Electron ◽  
Wide Range

The coherence of the electron flux of a transmission electron microscope (TEM) limits the direct application of deconvolution techniques which have been used successfully on unmanned spacecraft programs. The theory assumes noncoherent illumination. Deconvolution of a TEM micrograph will, therefore, in general produce spurious detail rather than improved resolution.A primary goal of our research is to study the performance of several types of linear spatial filters as a function of specimen contrast, phase, and coherence. We have, therefore, developed a one-dimensional analysis and plotting program to simulate a wide 'range of operating conditions of the TEM, including adjustment of the:(1) Specimen amplitude, phase, and separation(2) Illumination wavelength, half-angle, and tilt(3) Objective lens focal length and aperture width(4) Spherical aberration, defocus, and chromatic aberration focus shift(5) Detector gamma, additive, and multiplicative noise constants(6) Type of spatial filter: linear cosine, linear sine, or deterministic

Luminescence from individual dislocations in II-VI and III-V semiconductors

1991 ◽  
Vol 49 ◽  
pp. 834-835
Author(s):  
J W Steeds
Keyword(s):  
Group Iv ◽  
Luminescence Properties ◽  
Carrier Recombination ◽  
Transmission Electron ◽  
Wide Range ◽  
Basic Physics ◽  
Semiconducting Compounds ◽  
Diamond Group ◽  
Non Destructive ◽  
Technological Significance

There is a wide range of experimental results related to dislocations in diamond, group IV, II-VI, III-V semiconducting compounds, but few of these come from isolated, well-characterized individual dislocations. We are here concerned with only those results obtained in a transmission electron microscope so that the dislocations responsible were individually imaged. The luminescence properties of the dislocations were studied by cathodoluminescence performed at low temperatures (~30K) achieved by liquid helium cooling. Both spectra and monochromatic cathodoluminescence images have been obtained, in some cases as a function of temperature.There are two aspects of this work. One is mainly of technological significance. By understanding the luminescence properties of dislocations in epitaxial structures, future non-destructive evaluation will be enhanced. The second aim is to arrive at a good detailed understanding of the basic physics associated with carrier recombination near dislocations as revealed by local luminescence properties.

Structural and electronic properties of defects in semiconductors

1995 ◽  
Vol 53 ◽  
pp. 4-5
Author(s):  
J.L. Batstone
Keyword(s):  
Semiconductor Device ◽  
Chemical Vapor ◽  
Misfit Strain ◽  
Organic Chemical ◽  
Extended Defects ◽  
Transmission Electron ◽  
Semiconductor Thin Films ◽  
Wide Range ◽  
Metal Organic ◽  
Film Substrate

The development of growth techniques such as metal organic chemical vapor deposition (MOCVD) and molecular beam epitaxy during the last fifteen years has resulted in the growth of high quality epitaxial semiconductor thin films for the semiconductor device industry. The III-V and II-VI semiconductors exhibit a wide range of fundamental band gap energies, enabling the fabrication of sophisticated optoelectronic devices such as lasers and electroluminescent displays. However, the radiative efficiency of such devices is strongly affected by the presence of optically and electrically active defects within the epitaxial layer; thus an understanding of factors influencing the defect densities is required.Extended defects such as dislocations, twins, stacking faults and grain boundaries can occur during epitaxial growth to relieve the misfit strain that builds up. Such defects can nucleate either at surfaces or thin film/substrate interfaces and the growth and nucleation events can be determined by in situ transmission electron microscopy (TEM).

The Problem of Identifying and Modeling the Relationship between Monetary Factor and Inflation in the Russian Economy

2008 ◽  
pp. 61-76
Author(s):  
A. Porshakov ◽  
A. Ponomarenko
Keyword(s):  
Money Supply ◽  
Money Demand ◽  
Russian Economy ◽  
Long Run ◽  
Complex Approach ◽  
Wide Range ◽  
Long Time ◽  
The Relationship ◽  
Supply Side Factors

The role of monetary factor in generating inflationary processes in Russia has stimulated various debates in social and scientific circles for a relatively long time. The authors show that identification of the specificity of relationship between money and inflation requires a complex approach based on statistical modeling and involving a wide range of indicators relevant for the price changes in the economy. As a result a model of inflation for Russia implying the decomposition of inflation dynamics into demand-side and supply-side factors is suggested. The main conclusion drawn is that during the recent years the volume of inflationary pressures in the Russian economy has been determined by the deviation of money supply from money demand, rather than by money supply alone. At the same time, monetary factor has a long-run spread over time impact on inflation.

Fin Level Defect Isolation Inside a FinFET Using Electron Beam Alteration of Current Flow

2017 ◽  
Author(s):  
H.J. Ryu ◽  
A.B. Shah ◽  
Y. Wang ◽  
W.-H. Chuang ◽  
T. Tong
Keyword(s):  
Electron Microscopy ◽  
Electron Beam ◽  
Focused Ion Beam ◽  
Current Flow ◽  
Ion Beam ◽  
The Body ◽  
Complete Understanding ◽  
Root Cause ◽  
Transmission Electron ◽  
Defect Isolation

Abstract When failure analysis is performed on a circuit composed of FinFETs, the degree of defect isolation, in some cases, requires isolation to the fin level inside the problematic FinFET for complete understanding of root cause. This work shows successful application of electron beam alteration of current flow combined with nanoprobing for precise isolation of a defect down to fin level. To understand the mechanism of the leakage, transmission electron microscopy (TEM) slice was made along the leaky drain contact (perpendicular to fin direction) by focused ion beam thinning and lift-out. TEM image shows contact and fin. Stacking fault was found in the body of the silicon fin highlighted by the technique described in this paper.

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