The task of materials scientists is to create stronger, lighter, and better materials, materials with new and useful properties. One very helpful tool for understanding materials would be a microscope powerful enough to "see" individual atoms.
Now a new electron microscope at Berkeley Labs can produce images of individual atoms. The microscope, which is called TEAM 0.5, produces images with half-angstrom resolution. This is less than the diameter of a single hydrogen atom.
TEAM stands for Transmission Electron Aberration-corrected Microscope. Electron microscopes use a beam of electrons instead of visable light. The quality of what is seen through a microscope is dependent upon correcting lens aberration and upon the alignment and quality of all the components.
The information limit of a microscope results from mechanical and electromagnetic instabilities. Recent technological advances make it possible to improve mechanical stability by increasing the column’s mechanical stiffness, and to reduce electromagnetic instabilities by stabilizing the fields to an accuracy of about 100 parts per billion. These measures will extend the information limit beyond 0.05 nanometer. National Center for Electron Microscopy at Lawrence Berkeley National Laboratory
Although bright light makes for better viewing, the equivalent high energy electron beams often destroy what is being looked at. The TEAM 0.5 microscope can now provide good viewing of sensitive targets with electron beam intensities as low as 80kV. Low energy electron beams will allow visualizing organic samples.
The TEAM 0.5 microscope was used to look at a sheet of graphene. Individual atoms of carbon can be seen in the honeycomb shaped image. (click this link for the "Closest look ever at graphene")
The position of individual atoms in a structure can be determined by taking images at different angles, from which the computer reconstructs a 3-D tomograph of the sample, as in a CAT scan. To make this possible an innovative system capable of tilting and rotating the sample, and moving it up, down, or sideways under the electron beam, is also being developed at NCEM.
The current version of microscope, the TEAM 0.5, will be available to users next month. The next version, the TEAM I, will have even greater capablities.
Manipulating the sample by such methods as minute piezoelectric "crawlers" that change shape when electricity is applied, the new stage will be able to control and reproduce the sample's position and attitude with an accuracy of less than a billionth of a meter.
Click this link to see the timetable of TEAM development