 |
|
A snapshot of the transformation
September 12, 2008LIVERMORE, Calif. - Researchers have achieved a milestone in materials science and electron microscopy by taking a high-resolution snapshot of the transformation of nanoscale structures.
Using the Lab's Dynamic Transmission Electron Microscope (DTEM), Judy Kim and colleagues peered into the microstructure and properties of reactive multilayer foils (also known as nanolaminates) with 15-nanosecond-scale resolution.
"This is the first time that a detailed study of these reactive nanolaminates has exposed what is happening in the self-propagating high-temperature synthesis zone," Kim said.
Time-resolved images of nanolaminates show a brief change in structure with a short cellular phase separation during cooling.
Observing short-lived behavior - how a chemical reaction, structural deformation or phase transformation occurs - is not easy, but is key to understanding many of the basic phenomena at the heart of chemistry, biology and materials science. The ability to directly observe and characterize these complex events leads to a fundamental understanding of properties such as reactivity, stability and strength, and helps in the design of new and improved materials and devices.
Transmission electron microscopy has evolved dramatically in recent years and can spatially resolve microstructural details of phase and structure, but it can't collect at times less than a millisecond.
That's where Livermore's DTEM comes in. It provides scientists with the ability to image transient behavior with an unprecedented combination of spatial and temporal resolution: nanometers and nanoseconds.
"Direct real-space observations of phase transformations on the nanosecond scale have allowed us to relate the formation mechanism in reactive multilayer foils to binary alloy solidification," Kim said. "This conclusion is based upon transient features that could not have been found using any other technique."
Because the team needed access to time and real-space that is impossible to study using traditional methods such as conventional in situ TEM (limited to video rates) or ultrafast diffraction (which presently lacks direct real-space imaging capabilities), the DTEM fit the bill.
"The ability to determine not only crystal structure, but also morphological evolution of dynamic events on the nanoscale has far-reaching implications for the study of materials science, non-equilibrium processes and the behavior of matter on very fine scales of length and time," Kim said.
Multilayer foils are layers of reactant materials that undergo exothermic, self-propagating reactions when layer mixing is caused by an external energy source. The foils show mobile, high-temperature reaction zones where atoms of adjoining layers diffuse across the interfaces. They are used as customized heat sources for rapid fuses, biological neutralization and joining materials via localized heating rather than global device heating.
LIVERMORE, Calif. - Researchers have achieved a milestone in materials science and electron microsco
Time-resolved images of nanolaminates show a brief change in structure with a short cellular phase separation during cooling.
Observing short-lived behavior - how a chemical reaction, structural deformation or phase transformation occurs - is not easy, but is key to understanding many of the basic phenomena at the heart of chemistry, biology and materials science. The ability to directly observe and characterize these complex events leads to a fundamental understanding of properties such as reactivity, stability and strength, and helps in the design of new and improved materials and devices.
Transmission electron microscopy has evolved dramatically in recent years and can spatially resolve microstructural details of phase and structure, but it can't collect at times less than a millisecond.
That's where Livermore's DTEM comes in. It provides scientists with the ability to image transient behavior with an unprecedented combination of spatial and temporal resolution: nanometers and nanoseconds.
"Direct real-space observations of phase transformations on the nanosecond scale have allowed us to relate the formation mechanism in reactive multilayer foils to binary alloy solidification," Kim said. "This conclusion is based upon transient features that could not have been found using any other technique."
Because the team needed access to time and real-space that is impossible to study using traditional methods such as conventional in situ TEM (limited to video rates) or ultrafast diffraction (which presently lacks direct real-space imaging capabilities), the DTEM fit the bill.
"The ability to determine not only crystal structure, but also morphological evolution of dynamic events on the nanoscale has far-reaching implications for the study of materials science, non-equilibrium processes and the behavior of matter on very fine scales of length and time," Kim said.
Multilayer foils are layers of reactant materials that undergo exothermic, self-propagating reactions when layer mixing is caused by an external energy source. The foils show mobile, high-temperature reaction zones where atoms of adjoining layers diffuse across the interfaces. They are used as customized heat sources for rapid fuses, biological neutralization and joining materials via localized heating rather than global device heating.
LIVERMORE, Calif. - Researchers have achieved a milestone in materials science and electron microsco
Electron Microscopy Current Events and Electron Microscopy News RSSScripps Research Scientists Shed Light on How DNA Is Unwound So That Its Code Can Be Read
Researchers at The Scripps Research Institute have figured out how a macromolecular machine is able to unwind the long and twisted tangles of DNA within a cell's nucleus so that genetic information can be "read" and used to direct the synthesis of proteins, which have many specific functions in the body.
Pure insulin-producing cells produced in mouse
Singapore researchers have developed an unlimited number of pure insulin-producing cells from mouse embryonic stem cells (ESCs).
Very cold ice films in laboratory reveal mysteries of universe
The universe is full of water, mostly in the form of very cold ice films deposited on interstellar dust particles, but until recently little was known about the detailed small scale structure.
Protein 'tubules' free avian flu virus from immune recognition
A protein found in the virulent avian influenza virus strain called H5N1 forms tiny tubules in which it "hides" the pieces of double-stranded RNA formed during viral infection, which otherwise would prompt an antiviral immune response from infected cells, said Baylor College of Medicine researchers in an online report in the journal Nature.
McMaster University unveils world's most advanced microscope
The most advanced and powerful electron microscope on the planet-capable of unprecedented resolution-has been installed in the new Canadian Centre for Electron Microscopy at McMaster University.
Engineering Nanoparticles for Maximum Strength
Because they are riddled with defects, bulk crystalline materials never achieve their ideal strength; nanocrystals, on the other hand, are so small there's no room for defects.
Caltech biologists spy on the secret inner life of a cell
The transportation of antibodies from a mother to her newborn child is vital for the development of that child's nascent immune system.
Structures of Important Plant Viruses Determined
Flexible filamentous viruses make up a large fraction of known plant viruses and are responsible for more than half the viral damage to crop plants throughout the world.
NIST and partners identify tiny gold clusters as top-notch catalysts
For most of us, gold is only valuable if we possess it in large-sized pieces. However, the "bigger is better" rule isn't the case for those interested in exploiting gold's exceptional ability to catalyze a wide variety of chemical reactions, including the oxidation of poisonous carbon monoxide (CO) into harmless carbon dioxide at room temperatures.
Tracking Down the Menace in Mexico City Smog
A new report by scientists who are part of the international MILAGRO Campaign indicates that some of the most harmful air pollution in Mexico City may not come from motor vehicles but instead originates with industrial sources - and that the culprit may be garbage incineration.
More Electron Microscopy Current Events and Electron Microscopy News Articles
| Transmission Electron Microscopy: A Textbook for Materials Science by David B. Williams, C. Barry Carter This groundbreaking text provides the necessary instructions for hands-on application of this versatile materials characterization technique and is supported by over 600 illustrations and... | |
 | Scanning Electron Microscopy and X-ray Microanalysis by Joseph Goldstein, Dale E. Newbury, David C. Joy, Charles E. Lyman, Patrick Echlin, Eric Lifshin, L.C. Sawyer, J.R. Michael Providing a comprehensive introduction to the capabilities and use of scanning electron microscopes (SEM) and x-ray spectrometers, this highly acclaimed text emphasizes practical aspects of imaging and analysis for a broad audience of students and practitioners whose backgrounds span a wide range of science and technology. Topics discussed include user-controlled functions of scanning electron... |
 | Electron Microscopy of Polymers (Springer Laboratory) by Goerg H. Michler There are many books on electron microscopy, however, the study of polymers using EM necessitates special techniques, precautions and preparation methods, including ultramicrotomy. This book discusses the general characteristics of the various techniques of EM, including scanning force microscopy (AFM). The application of these techniques to the study of morphology and properties, particularly... |
 | Manual of Applied Techniques for Biological Electron Microscopy by Michael J. Dykstra North Carolina State University, Raleigh. Handbook of step-by-step techniques in the preparation and study of specimens using electron microscopy. Wire spiral binding. Halftone... |
 | Electron Microprobe Analysis and Scanning Electron Microscopy in Geology by S. J. B. Reed Now fully updated to cover recent developments, this book covers the closely related techniques of electron microprobe analysis (EMPA) and scanning electron microscopy (SEM) specifically from a geological viewpoint. Topics discussed include: principles of electron-target interactions, electron beam instrumentation, X-ray spectrometry, general principles of SEM image formation, production of X-ray... |
 | Scanning Electron Microscopy: Physics of Image Formation and Microanalysis (Springer Series in Optical Sciences) by Ludwig Reimer Scanning Electron Microscopy provides a description of the physics of electron-probe formation and of electron-specimen interactions. The different imaging and analytical modes using secondary and backscattered electrons, electron-beam-induced currents, X-ray and Auger electrons, electron channelling effects, and cathodoluminescence are discussed to evaluate specific contrasts and to obtain... |
 | Electron Microscopy, 2nd Edition by John J. Bozzola, Lonnie Dee Russell Electron Microscopy covers all of the important aspects of electron microscopy for biologists, including theory of scanning and transmission, specimen preparation, digital imaging and image analysis, laboratory safety and interpretation of images. The text also contains a complete atlas of... |
 | Electron Microscopy: Methods and Protocols (Methods in Molecular Biology) In this revised and expanded second edition, Electron Microscopy: Methods and Protocols presents the newest technology in electron microscopy, while maintaining the practicality and accessibility of the acclaimed first edition. Like the first edition, this volume provides clear, concise instructions on processing biological specimens and includes discussion on the underlying principles of the... |
 | Transmission Electron Microscopy: Physics of Image Formation (Springer Series in Optical Sciences) by L. Reimer, H. Kohl Transmission Electron Microscopy presents the theory of image and contrast formation, and the analytical modes in transmission electron microscopy. The principles of particle and wave optics of electrons are described. Electron-specimen interactions are discussed for evaluating the theory of scattering and phase contrast. Also discussed are the kinematical and dynamical theories of electron... |
 | Physical Principles of Electron Microscopy: An Introduction to TEM, SEM, and AEM by Ray F. Egerton Scanning and stationary-beam electron microscopes have become an indispensable tool for both research and routine evaluation in materials science, the semiconductor industry, nanotechnology, and the biological and medical sciences. Physical Principles of Electron Microscopy provides an introduction to the theory and current practice of electron microscopy for undergraduate students who want to... |
| © 2008 BrightSurf.com |