Tickling Atoms and Testing Theories
High-angle dark-field STEM image of discrete tungsten atoms (bright dots) on aluminum-oxide. Image by Ke-Bin Low
“With this new Scanning Transmission Electron Microscope we can see atoms at a resolution previously unattainable. We are primarily studying hard, condensed matter—non-biologic material—and actually measuring how those atoms bond. We can look at one atom and probe or ‘tickle’ it to see how it bonds to a neighboring atom. This is unprecedented,” said Robert Klie, associate professor in the Department of Physics.
The microscope in question—informally referred to as the STEM and formally known as the UIC JEOL JEM-ARM200CF—is the first instrument in the United States with such a high level of capability. With this equipment, researchers will be able to visualize 0.7 of an angstrom, the unit of length used in science and technology to express the sizes of atoms and their arrangement in crystals, molecules and nanostructures. An angstrom is equal to one ten-billionth of a meter. “In telescopic terms, it is like standing on the earth and being able to see a dime on the moon,” explained Alan Nicholls, director of electron microscopy service in the UIC Research Resources Center.
“Things that were previously predicted by condensed-matter physics of chemistry theory can now actually be visualized, probed and tested, allowing us to further improve the theoretical models. Such improved theories will ultimately lead to better, more efficient or environmentally-friendly materials,” noted Klie.
Robert Klie (left) and John Fudacz, LAS assistant dean.
Klie is the man responsible for securing the $2 million National Science Foundation grant that brought the STEM to the RRC. “When I came to UIC from Brookhaven National Lab the STEM in the RRC was nearly ten years old. Although it had been one of the highest-resolution instruments in 1998, it was unfortunately outdated. I tried several times to get a Major Research Instrumentation grant from the NSF to upgrade and retrofit that instrument with an aberration corrector,” explained Klie, who joined the physics faculty in 2007. “Simply put, I was seeking a pair of glasses for the electrons to sharpen up the image. We were close, but that project never got funded.”
Ke-Bin Low (standing) and Alan Nicholls work at the STEM.
Stimulus money distributed to the NSF resulted in the agency designating a large portion of the funds to new instrumentation. “A completely new microscope fit into the grant guidelines, so I went for it,” said Klie. “In 2008-2009, when I was writing and submitting the grant, some of the new components of the STEM did not yet exist. I talked to several manufacturers including JEOL—the company that manufactured our existing equipment—about what they were developing, because I wanted to make sure that we would get a device that would be at the forefront of science for years to come.”
“I want to acknowledge the invaluable contributions of my many collaborators throughout the university in the preparation of the grant,” noted Klie, who added that contributions from LAS, the Colleges of Engineering and Public Health and the Office of the Vice Chancellor for Research provided an additional $1 million to purchase the microscope.
The STEM was delivered during the summer of 2011, with installation completed and certified as the fall semester came to an end. The microscope’s home in the RRC East is sound- and temperature-controlled. Four temperature probes are suspended from the ceiling to ensure that the cold-water cooling panels keep the room at the optimum 70 degrees, plus or minus point one. Recycled denim lines the walls for sound baffling. “We have to control air flow so people can still breathe, but there cannot be too much air flow,” said Klie. “Any sort of air movement will shake the column and destabilize the pictures.”
Left to right: Robert Klie, Astrida Orle Tantillo, Peter C. Nelson, Joe “Skip” Garcia.
On January 20, 2012 scientists and their supporters gathered in the RRC for a reception and ribbon-cutting ceremony officially welcoming the equipment to Science and Engineering South. Klie provided welcome and introductory remarks, giving an overview of the capabilities of the STEM. Astrida Orle Tantillo, interim dean of LAS; Peter C. Nelson, dean of the College of Engineering; and Joe “Skip” Garcia, then-vice chancellor for research, offered congratulations and kudos, acknowledging the outstanding collaboration across departments and colleges of the university. David Hofman, acting head of physics, provided a heartfelt nod to scientific pioneers and an inspiring view to “the new research, and the new science, and the new materials discoveries that this instrument will enable to occur.”
As work with the STEM begins in earnest, a maximum of ten researchers per week are admitted to the microscope’s chapel-like environs—after receiving training from Ke-Bin Low, RRC senior research specialist and Alan Nicholls, the team responsible for operation and maintenance of the microscope. Patrick Phillips, research faculty, will collaborate with RRC staff and serve as the scientific leader on many of the projects. He will also assist with high-end training of students and industrial and academic partners.
Klie and some of his PhD students. Left to right: Ahmet Gulec, Jingjing Liu, Robert Klie, Qiao Qiao.
STEM users include faculty and doctoral students from UIC partner departments including physics, chemistry and earth and environmental science; chemical, electrical and biological engineering; and public health. “The three main career branches that our STEM-using students will be entering are university-based teaching and research, research in national labs, and industrial research,” said Klie, who serves as Principal Investigator for the Department of Physics’ Nanoscale Physics Group.
Much of the research utilizing the new power of the STEM will involve looking at nanostructure materials, including catalysts. For example, just a tiny fraction of improvement in the efficiency of the catalysts that generate fuel, diesel, polymers and alcohol will result in major improvements in products for the petrochemical industry. “There is huge interest from companies such as BP, Shell and Exxon Mobile to look at these nano-catalysts,” said Klie, who noted that his research group has already attracted new funding and contracts based on using the STEM. “Without this equipment we would not have attracted these grants and collaborations.
...improved theories will ultimately lead to better, more efficient or environmentally-friendly materials.
“I have funding right now for several projects in the general area of green research. In one study, we are looking at rhodium-based catalysts that will allow us to gasify plant-waste material and use catalysts with these gases to convert into ethanol alcohol. The basic idea is to create an alternative fuel source from sources other than petrochemicals or corn. This is hugely important for alternative energy production.”
The STEM also allows researchers to look at the atomic structure of larger-scale ceramic materials and improve the materials “by tinkering with the atomic structure.”
Klie’s group is currently working on a project in thermo-electrics that allow the conversion of waste heat into electricity. “Eighty percent of the heat we produce is wasted—in your house, your car, in industrial processes. By improving the properties of the thermo-electric material at the point of the atomic bond, the conversion of waste heat into electricity can be significantly increased which could lead to an overall reduction of 30 billion kg of CO2 emission per year,” he explained.
“The result of this increased efficiency would make it possible, for example, for the temperature difference between the furnace in your house and the ambient air temperature to be used to create electricity, which would then power the electronics in your furnace or other home appliances. We could also use the temperature difference between your car’s engine block and the ambient air to power the car stereo or air conditioning unit, thereby reducing the overall fuel consumption of the vehicle. It’s better living through physics.”
Photos by Matthew Kaplan unless otherwise indicated