A microscope measuring picometers

A few months ago, I've written about the most powerful microscope in the world which was able to display images at an incredible high-resolution of just 0.05 nanometer (or 50 picometers). It seems that German scientists also have pushed electron microscopy to the picometer scale and broke the record for the highest-resolution images ever seen. The German team said they were able to 'microscopically measure atomic displacements precisely to a few picometers.' According to the scientists, it is possible to see atoms moving by only 10 picometers (or 0.01 nanometer). This could open new paths for research about physics of materials. But read more...

You can see above a photo of Professor Knut Urban and his staff discussing "the atomic structure of an oxide thin layer structure used for nanoelectronic applications which is revealed in an electron microscope image." (Credit: Forschungszentrum Jülich, link to a larger version).

Knut Urban is the director of the Ernst Ruska-Centre in Jülich, a joint research platform operated by Forschungszentrum Jülich and RWTH Aachen University. Forschungszentrum Jülich is a member of the Helmholtz Association of German Research Centers. "As a national user centre, it provides researchers from science and industry with access to the most powerful electron microscopes currently available." Urban also works for the Institute of Solid State Research (IFF) which focuses on condensed matter research.

You can see above an example of an application of this technology. [Note: the caption is quite long, but essential for understanding the concept described.] "Using electron microscope methods of a hitherto unknown accuracy, scientists from Forschungszentrum Jülich have succeeded in locally demonstrating polarisation in the ferroelectric PbZr_0.2Ti_0.8O₃ and measuring it atom by atom. The broken line forms the boundary of two areas with different electrical polarisation marked by the arrows. This is due to the fact that the atoms (Pb: lead; Z: zircon; Ti: titanium; O: oxygen) are displaced from their positions and therefore their electrical charges cannot compensate for each other. On the left, the oxygen atoms are displaced 38 pm downwards, and on the right to the same degree upwards out of the zircon/titanium atomic row. This row itself is displaced vertically by 10 pm from the centre line between the lead atoms. In order to write information in applications for data storage, the boundary between these two areas of different polarisation directions is displaced to the left or to the right so that only one polarisation direction exists in the material." (Credit: Forschungszentrum Jülich, link to a larger version).

Here is another example taken from the Helmholtz Association news release. "Jülich scientists investigated, for example, the configuration of atoms in orthogonal grain boundaries of the oxide superconductor YBa₂Cu₃O₇. These atoms mark the boundary between two areas of the crystalline material with atomic structures that are tilted at an angle of exactly 90° to each other. From microscopic images taken under different conditions, the physicists succeeded in using computers to calculate the quantum-mechanical wave function of the electrons, which served as a basis for determining the exact position of the atoms."

This research work has been published in Science under the name "Studying Atomic Structures by Aberration-Corrected Transmission Electron Microscopy" (Volume 321, Issue 5888, Pages 506-510, July 25, 2008).

Here is an excerpt from the abstract. "An entirely new generation of instruments enables studies in condensed-matter physics and materials science to be performed at atomic-scale resolution. These new possibilities are meeting the growing demand of nanosciences and nanotechnology for the atomic-scale characterization of materials, nanosynthesized products and devices, and the validation of expected functions. Equipped with electron-energy filters and electron-energy–loss spectrometers, the new instruments allow studies not only of structure but also of elemental composition and chemical bonding. The energy resolution is about 100 milli–electron volts, and the accuracy of spatial measurements has reached a few picometers."

It's interesting to note that the German team doesn't say anything about the cost of such a microscope. It doesn't say either when this technology can become available to other research centers around the world.

Sources: Helmholtz Association of German Research Centres news release, July 24, 2008; and various websites

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