Montana State receives NSF grant for sophisticated X-ray photoelectron spectrometer

BOZEMAN - A Montana State University core research facility described by its director as a "portal to the magical world of nanoscience" has received funding for a sophisticated instrument to support multidisciplinary research at MSU and across the state.

The National Science Foundation's Division of Materials Research and EPSCoR program have awarded $833,000 for a new X-ray Photoelectron Spectroscopy system. The new instrument will be housed in MSU's Imaging and Chemical Analysis Laboratory in Barnard Hall and will restore the small-spot elemental and chemical surface analysis capability lost when the former, 25-year old XPS spectrometer became irreparable in 2020.

News of the grant was a welcome gift for ICAL, awarded on the facility's 33rd birthday in September. Since 2015, ICAL has been one of six MSU labs in the Montana Nanotechnology Facility, an NSF-supported user consortium. ICAL is home to numerous instruments used by physicists, chemists, microbiologists, geologists, engineers and other researchers to characterize the microscopic chemical and physical properties of materials. ICAL director and founder Recep Avci said the original XPS was among the first essential instruments the facility acquired to support surface and interface science research at MSU.

Demand for XPS analysis is perhaps even greater today, according to Rob Walker, head of MSU's Department of Chemistry and Biochemistry in the College of Letters and Science, who led the campus-wide effort to secure the grant for the new instrument. He said the spectrometer will advance research activities at MSU and across Montana in quantum materials, energy storage and conversion, biomineralization and environmental science.

"The XPS spectrometer is a foundational tool for any R1 university engaged in materials research," said Walker, referring to MSU's Carnegie designation as a university with very high research activity. "Not having this capability was a real gap in MSU's portfolio, and the interdisciplinary team effort to write this grant will benefit research and education across the entire campus."

ICAL houses high-resolution imaging and spectroscopy instrumentation to explore the size, shape, textures and structure of materials at the nanoscale. But unlike the other instruments in the facility, including its electron microscopes, the XPS will provide detailed elemental and chemical information about the composition of a material's surface at any given point, down to the level of 5 to 10 nanometers. A nanometer is 1/1000th of a micron, and a micron measures 1/1000th of a millimeter, or about 1/25,000th of an inch.

Stephen Sofie, a co-PI on the NSF proposal and a professor in MSU's Department of Mechanical and Industrial Engineering in the Norm Asbjornson College of Engineering, said the XPS will provide critical support for his ceramic materials research including his investigations of MIECs, or mixed ionic and electrically conducting ceramics. These materials are candidates for new direct energy conversion applications, such as fuel cells and solid-state batteries. These specific MIECs synthesized at MSU, called perovskites, can conduct electricity as efficiently as stainless steel, which is uncommon in ceramics yet pivotal to practical scaling of devices for commercial applications.

Sofie believes that the unusually high conductivity may be due to the valence states of molybdenum and vanadium in the material. Valence states determine the manner in which atoms combine and interact with other groups of atoms. The new XPS will be able to examine those valence states when the materials are heated to the operating temperatures of direct energy conversion applications.

"We're very excited with this new XPS so we can study the valence state evolution as a function of both the temperature and chemical stoichiometry," Sofie said. "We really think that it's a very careful coalition of valence states from processing that drives this transition to highly metallic behavior. If we can understand that, we can find new ways to engineer this unique material."

Stephanie Ewing, professor in MSU's Department of Land Resources and Environmental Sciences in the College of Agriculture and director of the Montana Water Center, said the XPS will further her study of water contamination in different environments. She is particularly interested in the movement of pesticides and other complex and human-made organic compounds toward and through groundwater.

"We will look to use this instrument to characterize soil and other mineral and organic-coated surfaces that slow down movement of environmental contaminants and control the release of solutes in waters," she said.

Nick Stadie, associate professor in the Department of Chemistry and Biochemistry, said the absence of XPS capability has been a challenge for his lab. The Stadie Group works to improve carbon- and silicon-based materials for optimal energy storage applications. The XPS provides an atomistic-scale perspective of how the materials are structured, helping the researchers understand which types of bonds exist.

"We can look at the structure before and after using it inside of a battery. In the case of silicon, it totally rearranges itself," he said. "This tool is going to revolutionize what we can do to make improvements."

Since the previous XPS unit at ICAL stopped working, Stadie added, he and his students have sent their materials to Maryland for analysis, which is far from an ideal solution.

"It slows us down a lot, because we're disadvantaged by not having students there who made the materials," he said. "The people performing the XPS measurements over there didn't make the samples. Now, having our students here put their own hands on the instrument is going to accelerate our research incredibly."

The XPS will be available to researchers not only at MSU but throughout the Montana University System, including tribal colleges. Stadie said his group has been collaborating on a project with students at Salish Kootenai College in Pablo, and he expects they will travel to Bozeman to use the XPS for their research.

"This really is a statewide effort coming together to demonstrate the need this capability, and those collaborative efforts were commented on time and time again in the (grant) reviews," Walker said. "The entire jurisdiction is going to benefit from this."

One function of MSU's core research facilities is to give students hands-on experience with the specialized equipment in each lab. ICAL staff will train students to use the new XPS, which is equipped with the latest technological innovations.

"It's nice to spend my professional life in a room and have students become experts," Avci said. "How can you beat that?"

Facility manager Sara Zacher, who was one of Avci's students 25 years ago, reiterated that XPS capability is an essential element of ICAL.

"It's our beating heart," she said. "We're very happy to get it back again."