Breaking the temperature barrier in small-scale materials testing

Researchers have demonstrated a new method for testing microscopic aeronautical materials at ultra-high temperatures. By combining electron microscopy and laser heating, scientists can evaluate these materials much more quickly ...

First view of hydrogen at the metal-to-metal hydride interface

University of Groningen physicists have visualized hydrogen at the titanium/titanium hydride interface using a transmission electron microscope. Using a new technique, they succeeded in visualizing both the metal and the ...

Turning up the heat to create new nanostructured metals

Scientists have developed a new approach for making metal-metal composites and porous metals with a 3-D interconnected "bicontinuous" structure in thin films at size scales ranging from tens of nanometers to microns. Metallic ...

Mysteries behind interstellar buckyballs finally answered

Scientists have long been puzzled by the existence of so-called "buckyballs"—complex carbon molecules with a soccer-ball-like structure—throughout interstellar space. Now, a team of researchers from the University of ...

Creating new opportunities from nanoscale materials

A hundred years ago, "2d" meant a two-penny, or 1-inch, nail. Today, "2-D" encompasses a broad range of atomically thin flat materials, many with exotic properties not found in the bulk equivalents of the same materials, ...

page 1 from 15

Transmission electron microscopy

Transmission electron microscopy (TEM) is a microscopy technique whereby a beam of electrons is transmitted through an ultra thin specimen, interacting with the specimen as it passes through. An image is formed from the interaction of the electrons transmitted through the specimen; the image is magnified and focused onto an imaging device, such as a fluorescent screen, on a layer of photographic film, or to be detected by a sensor such as a CCD camera.

TEMs are capable of imaging at a significantly higher resolution than light microscopes, owing to the small de Broglie wavelength of electrons. This enables the instrument to be able to examine fine detail—even as small as a single column of atoms, which is tens of thousands times smaller than the smallest resolvable object in a light microscope. TEM forms a major analysis method in a range of scientific fields, in both physical and biological sciences. TEMs find application in cancer research, virology, materials science as well as pollution and semiconductor research.

At smaller magnifications TEM image contrast is due to absorption of electrons in the material, due to the thickness and composition of the material. At higher magnifications complex wave interactions modulate the intensity of the image, requiring expert analysis of observed images. Alternate modes of use allow for the TEM to observe modulations in chemical identity, crystal orientation, electronic structure and sample induced electron phase shift as well as the regular absorption based imaging.

The first TEM was built by Max Knoll and Ernst Ruska in 1931, with this group developing the first TEM with resolving power greater than that of light in 1933 and the first commercial TEM in 1939.

This text uses material from Wikipedia, licensed under CC BY-SA