The Oak Ridge National Laboratory researchers is using a state of the art microscope and new computerized imaging technology pushing back the barrier of how small we can see. It is a record of up to atom scale 0.6 angstrom. The same lab, the ORNL, a Department of Energy national laboratory, also held the previous record at 0.7 angstrom. The researchers in ORNL obtained the improved resolution using the 300 kilovolt Z contrast scanning transmission electron microscope or STEM of the said lab, aided by an emerging technology called aberration correction. The direct images have been acknowledged as proof of atom scale resolution below one angstrom and provide researchers with a valuable tool for designing advanced materials. An ORNL Condensed Matter Sciences Division researcher claimed that with the electron microscope, we can see atoms that are only 0.78 angstroms apart. This is the first unequivocal proof that the electron microscope has a sub angstrom resolution. The same image, silicon crystal, shows that the electron microscope is getting resolution in the 0.6-angstrom range. An angstrom is an atomic scale unit of measure of one ten billionth of a meter, approximately equaling the diameter of an atom. The ORNL researchers teamed with the Nion Company. This is in order to produce the images of pairs of silicon atom columns in a crystal. The Kirkland, Wash firm provided the aberration correction technology that corrects errors introduced to the images by imperfections in the electron lenses. This aberration corrected microscopy provides a direct image with fewer opportunities for incorrect image information. Uncorrected microscopy can achieve sub angstrom resolution by combining a collection of many images to achieve an image, but it also increases the introduction of artifacts into the images. With aberration correction you can see everything better. You can see what is going on at the atomic scale including how atoms bond and how things work.The researchers further discusses that by revealing columns of atoms and the position of introduced, do pant, atoms, the atom scale images enable a new understanding of materials properties. The finer images also enable researchers to more accurately model. This also allowed them to predict the behavior of materials on computers before time-consuming and expensive bench tests are conducted. The latest ORNL images improve on the previous resolution of 0.7 angstrom, also achieved with ORNL’s Z contrast STEM. ORNL has recently constructed an advanced materials characterization laboratory that will further the application of aberration correction technologies to atom scale microscopy.
Original Text:
http://www.ornl.gov/info/press_releases/get_press_release.cfm?ReleaseNumber=mr20040917-00
