In Situ High Voltage Electron Microscopy Observations of Deformation and Fracture in Multilayered Materials

1995 ◽  
Vol 404 ◽  
Author(s):  
M. A. Wall ◽  
T. W. Barbee ◽  
T. P. Weihs
Keyword(s):  
Crack Nucleation ◽  
Free Standing ◽  
Cross Sectional ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
Transmission Electron ◽  
Deformation And Fracture ◽  
Gauge Section ◽  
Multilayered Materials

AbstractA novel, in situ transmission electron microcopy technique for the direct observation of deformation and fracture in multilayered materials oriented in cross-section is reviewed. Cross-sectional tensile specimens were prepared from thick, free-standing, Cu/Zr and Al/Ti multilayered foils. These tensile specimens contain a micro-gauge section, thus predetermining the location at which dislocation activity and crack nucleation and growth can be observed at high magnifications in the transmission electron microscope. The results from these experiments are unique and cannot be realized by any other technique. These observations will aid us in our understanding of the micromechanisms of deformation and fracture in multilayered materials.

scholarly journals An in Situ High Voltage Electron Microscopy Technique for the Study of Deformation and Fracture: in Multilayered Materials

1995 ◽  
Vol 382 ◽  
Author(s):  
M.A. Wall ◽  
T.W. Barbee ◽  
T.P. Weihs
Keyword(s):  
High Voltage ◽  
Tensile Deformation ◽  
Specimen Preparation ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
Microscopy Technique ◽  
High Voltage Electron ◽  
Deformation And Fracture ◽  
Multilayered Materials

ABSTRACTA novel, in situ, high voltage electron microcopy technique for the direct observation of the micromechanisms of tensile deformation and fracture in nanostructured materials is detailed. This technique is particularly well suited for the dynamic observations of deformation and fracture in multilayered materials. The success of this type of in situ technique is highly dependent upon unique specimen preparation procedures and sample design, the importance thereof will be discussed. The initial observations discussed here are expected to aid in our understanding of the mechanical behavior of this new class of atomically engineered materials.

scholarly journals Preparation of Multilayered Materials in Cross-Section for in-Situ Tem Tensile Deformation Studies

1997 ◽  
Vol 480 ◽  
Author(s):  
M. A. Wall ◽  
T. W. Barbee
Keyword(s):  
Focused Ion Beam ◽  
Tensile Deformation ◽  
Crack Nucleation ◽  
Ion Beam ◽  
Specimen Preparation ◽  
In Situ Tem ◽  
Transmission Electron ◽  
Gauge Section ◽  
In Situ Deformation

AbstractThe success of in-situ transmission electron microscopy experimentation is often dictated by proper specimen preparation. We report here a novel technique permitting the production of crosssectioned tensile specimens of multilayered films for in-situ deformation studies. Of primary importance in the development of this technique is the production of an electron transparent microgauge section using focused ion beam technology. This micro-gauge section predetermines the position at which plastic deformation is initiated; crack nucleation, growth and failure are then subsequently observed.

Direct Observation of Crack Propagation in Copper–Niobium Multilayers

2012 ◽  
Vol 134 (2) ◽  
Author(s):  
K. Hattar ◽  
A. Misra ◽  
M. R. F. Dosanjh ◽  
P. Dickerson ◽  
I. M. Robertson ◽  
...  
Keyword(s):  
Crack Propagation ◽  
Dislocation Slip ◽  
Metallic Multilayers ◽  
Free Standing ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Length Scale Dependent Deformation ◽  
Crack Blunting ◽  
Nanoscale Metallic Multilayers

The failure of a cross-sectional 65 nm-thick copper and 150 nm-thick niobium multilayer thin film was investigated via an in situ transmission electron microscopy straining experiment. The fracture of the free-standing multilayer films was associated with confined dislocation slip within layers containing and preceding the crack tip. Four crack hindrance mechanisms were observed to operate during crack propagation: microvoid formation, crack deviation, layer necking, and crack blunting. Failure was observed to occur across and through the copper and niobium layers but never within the interfaces or grain boundaries. These results are discussed relative to the length-scale-dependent deformation mechanisms of nanoscale metallic multilayers.

mRNA localization by Electron microscopic in situ hybridization

1991 ◽  
Vol 49 ◽  
pp. 430-431
Author(s):  
J. A. Pollock ◽  
M. Martone ◽  
T. Deerinck ◽  
M. H. Ellisman
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Nucleic Acids ◽  
Recombinant Dna ◽  
Light And Electron Microscopy ◽  
Electron Microscopic ◽  
High Voltage Electron Microscopy ◽  
Functional Sites ◽  
Voltage Electron

Localization of specific proteins in cells by both light and electron microscopy has been facilitate by the availability of antibodies that recognize unique features of these proteins. High resolution localization studies conducted over the last 25 years have allowed biologists to study the synthesis, translocation and ultimate functional sites for many important classes of proteins. Recently, recombinant DNA techniques in molecular biology have allowed the production of specific probes for localization of nucleic acids by “in situ” hybridization. The availability of these probes potentially opens a new set of questions to experimental investigation regarding the subcellular distribution of specific DNA's and RNA's. Nucleic acids have a much lower “copy number” per cell than a typical protein, ranging from one copy to perhaps several thousand. Therefore, sensitive, high resolution techniques are required. There are several reasons why Intermediate Voltage Electron Microscopy (IVEM) and High Voltage Electron Microscopy (HVEM) are most useful for localization of nucleic acids in situ.

Contrast and Resolution in Alfresco Microscopy and Thick Specimens

1972 ◽  
Vol 30 ◽  
pp. 570-571
Author(s):  
J. R. Sellar ◽  
J. M. Cowley
Keyword(s):  
Solid Material ◽  
Cell Design ◽  
Current Interest ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
Transmission Electron ◽  
Environmental Cell ◽  
Scanning Transmission ◽  
Conventional Transmission Electron Microscope ◽  
Transmission Microscope

Current interest in high voltage electron microscopy, especially in the scanning mode, has prompted the development of a method for determining the contrast and resolution of images of specimens in controlled-atmosphere stages or open to the air, hydrated biological specimens being a good example. Such a method would be of use in the prediction of microscope performance and in the subsequent optimization of environmental cell design for given circumstances of accelerating voltage, cell gas pressure and constitution, and desired resolution.Fig. 1 depicts the alfresco cell of a focussed scanning transmission microscope with a layer of gas L (and possibly a thin window W) between the objective O and specimen T. Using the principle of reciprocity, it may be considered optically equivalent to a conventional transmission electron microscope, if the beams were reversed. The layer of gas or solid material after the specimen in the STEM or before the specimen in TEM has no great effect on resolution or contrast and so is ignored here.

Ultrastructural characteristics of sporidia of Ustilago

1989 ◽  
Vol 47 ◽  
pp. 786-787
Author(s):  
Patricia N. Hackney
Keyword(s):  
Electron Microscope ◽  
Type System ◽  
Tube Formation ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
University Of Wisconsin ◽  
Transmission Electron ◽  
Ustilago Hordei ◽  
Silene Alba ◽  
The University

Ustilago hordei and Ustilago violacea are yeast-like basidiomycete pathogens ofHordeum vulgare and Silene alba respectively. The mating type system in both species of Ustilago is bipolar, with alleles, A,a, (U.hordei) and a1, a2 (U.violacea) at a single locus. Haploid sporidia maintain the asexual phase by budding, while the sexual phase is initiated by conjugation tube formation between the mating types during budding and conjugation.For observation of budding, sporidia were prepared by culturing the four types on YEG (yeast extract glucose) broth for 24 hours. After centrifugation at 5000g cells were either left unmated or mated in a1/a2,A/a combinations. The sporidia were then mixed 1:1 with 4% agar and the resulting 1mm cubes fixed in 8% gluteraldehyde and post fixed in osmium tetroxide. After dehydration and embedding cubes were thin sectioned with a LKB ultratome and photographed in a Zeiss 9s transmission electron microscope or in an AE1 electron microscope of MK11 1MEV at the High Voltage Electron Microscopy Center of the University of Wisconsin-Madison.

On the interpretation of dislocation-loop growth during in-situ high-voltage Electron Microscopy

1990 ◽  
Vol 48 (4) ◽  
pp. 532-533
Author(s):  
E. Holzäpfel ◽  
F. Phillipp ◽  
M. Wilkens
Keyword(s):  
Point Defect ◽  
Rate Equations ◽  
Rate Theory ◽  
Dislocation Loops ◽  
High Voltage Electron Microscopy ◽  
Vacancy Migration ◽  
Voltage Electron ◽  
Reaction Rate Theory ◽  
Defect Reactions

During in-situ radiation damage experiments aiming on the investigation of vacancy-migration properties interstitial-type dislocation loops are used as probes monitoring the development of the point defect concentrations. The temperature dependence of the loop-growth rate v is analyzed in terms of reaction-rate theory yielding information on the vacancy migration enthalpy. The relation between v and the point-defect production rate P provides a critical test of such a treatment since it is sensitive to the defect reactions which are dominant. If mutual recombination of vacancies and interstitials is the dominant reaction, vαP0.5 holds. If, however, annihilation of the defects at unsaturable sinks determines the concentrations, a linear relationship vαP is expected.Detailed studies in pure bcc-metals yielded vαPx with 0.7≾×≾1.0 showing that besides recombination of vacancies and interstitials annihilation at sinks plays an important role in the concentration development which has properly to be incorporated into the rate equations.

A New Method of Wafer Level Plan View TEM Sample Preparation by DualBeam

2008 ◽  
Author(s):  
Hyoung H. Kang ◽  
Michael A. Gribelyuk ◽  
Oliver D. Patterson ◽  
Steven B. Herschbein ◽  
Corey Senowitz
Keyword(s):  
Sample Preparation ◽  
Ex Situ ◽  
Wafer Level ◽  
Cross Sectional ◽  
Plan View ◽  
Manufacturing Line ◽  
Transmission Electron ◽  
Thin Lamella ◽  
Preparation Techniques

Abstract Cross-sectional style transmission electron microscopy (TEM) sample preparation techniques by DualBeam (SEM/FIB) systems are widely used in both laboratory and manufacturing lines with either in-situ or ex-situ lift out methods. By contrast, however, the plan view TEM sample has only been prepared in the laboratory environment, and only after breaking the wafer. This paper introduces a novel methodology for in-line, plan view TEM sample preparation at the 300mm wafer level that does not require breaking the wafer. It also presents the benefit of the technique on electrically short defects. The methodology of thin lamella TEM sample preparation for plan view work in two different tool configurations is also presented. The detailed procedure of thin lamella sample preparation is also described. In-line, full wafer plan view (S)TEM provides a quick turn around solution for defect analysis in the manufacturing line.

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