October 18, 2010 –
Technicians uncrate the Quanta 3D before moving it in.
UCI chemists, physicists, materials scientists, biologists and medical researchers heaved a collective sigh of relief last week as a new scanning electron microscope/focused ion beam was installed in the microscopy lab at CALIT2.
The Quanta 3D FEG 600, manufactured by scientific instruments company FEI, replaces two other microscopes, the Ultra Plus and the EVO, which their owner, Carl Zeiss, Inc., recently relocated off campus.
“It became sort of an emergency,” said Matt Law, chair of the instrument’s oversight committee. “If we did not replace these capabilities, a lot of research groups would have had tremendous problems doing their research.”
The crisis created a groundswell of cross-campus collaboration. A consortium encompassing physical sciences, engineering, the medical school, CALIT2 and the Office of Research all contributed funds to purchase the instrument.
“It was a true example of multidisciplinary cooperation,” said CALIT2 Irvine Director G.P. Li. “Many different departments will benefit from this microscope and they all came together to bring it to campus.”
The effort was also well-timed. FEI had a demo instrument available at a discounted price and was able to deliver quickly. “It was very lucky,” Law said.
The Quanta 3D employs two columns: one emits electrons and the other emits ions (charged atoms). Each provides different functionality.
The electron column can provide images of the tiniest samples, those as small as 2.5 nanometers. (A human hair is approximately 70,000 nanometers in diameter.) Using accessories from Oxford Instruments, it offers elemental characterization, the ability to identify and map individual elements in the sample. In addition, it performs electron backscatter diffraction, a technique that allows an understanding of the crystal types in the sample’s components and their orientation in space and to each other.
Complete installation and calibration takes approximately a week.
While the ion beam produced by the second column can image samples just like the electron beam, its main function is different. Researchers can micro-fabricate with the ions – cutting, milling and drilling the sample to make circuits or thin sections of thick samples. “Literally, the ions come in and remove material by sputtering it from the surface,” Law said.
The ion beam can also be used to decompose molecules in the vacuum chamber. This produces nanoscale deposits of metals such as platinum, which is useful for making electrodes or bonding materials to one another.
An attachment called an Omniprobe – an extremely precise 3D nanomanipulator – will pick up small samples made by ion milling and place them elsewhere, often on a TEM (transmission electron microscopy) grid for further examination.
The applications are numerous. “Anyone making new types of materials who wants to know what those materials look like on a very, very small scale needs an electron microscope,” Law said. “What are the grain sizes, what are the shapes, how are things connected? Because that affects the material’s properties.”
Like the EVO before it, the Quanta 3D FEG can examine organic specimens as well, thanks to its environmental pressure chamber. Typical scanning electron microscopes create a vacuum around the sample, but the Quanta 3D can keep the specimens hydrated with a puff of moisture. “You can examine living matter, all the way down to cells and tissues, and keep them closer to what they would look like in the body or in a Petri dish,” explains Law.
The Quanta 3D will be available on a recharge basis to the campus and the wider community, and training classes will be offered over the next several months. “It’s important for continuity of research,” Law said. ”There’s a lot of unmet demand … and we need to keep the momentum going.”
–Anna Lynn Spitzer
