Feature Story | 18-Oct-2021

Scott chambers searches for new materials, one atomic layer at a time

Laboratory Fellow recognized globally as molecular-beam epitaxy authority

DOE/Pacific Northwest National Laboratory

By Allan Brettman

Scott Chambers grew up in San Diego, but he was destined for the Pacific Northwest. Pacific Northwest National Laboratory (PNNL) helped determine where he’d set down roots. His youthful search for a graduate degree program in chemistry, however, had a lot to do with setting the course.

With a bachelor’s degree in chemistry and chemical physics from the University of California at San Diego, Chambers had several graduate school options. A couple of distinguished universities had shown interest. But Oregon State University (OSU) would also provide a full fellowship. With an economic recession gripping the country in 1973, Chambers accepted. It helped that he already knew some OSU physical chemistry faculty members through his participation in a National Science Foundation summer research program at OSU between his junior and senior years at UC San Diego.

Did it also help that OSU’s campus in Corvallis was just an hour’s drive from surfing spots on the Oregon Coast? Did that sway the decision of the former UC San Diego surfing team member? Well, it didn’t hurt. Chambers can still rank his favorite Oregon Coast surf spots.

Most influential was his early life choice of a chemistry discipline.

“There's physical chemistry, inorganic chemistry, organic chemistry, biochemistry, analytical chemistry, nuclear chemistry, cosmochemistry, marine chemistry, among others,” Chambers said. “So there are many choices. But when I took my courses as an undergraduate, I had a fantastic professor for physical chemistry. And that's when I really got fired up about that subject. Once I took that course, I knew that was the area of chemistry I wanted to focus on.”

Today, Chambers is nearing the conclusion of a heralded career as a PNNL research scientist. Named a PNNL Laboratory Fellow in 2000 and a Wiley Research Fellow in 2009, Chambers has advanced our understanding of the nature and properties of complex metal oxide films and heterostructures. He has done so, colleagues say, with a meticulous, principled, and congenial approach. As he continues this research, Chambers is preparing to move from his labs in the Environmental Molecular Sciences Laboratory (EMSL), a DOE Office of Science user facility, to a prominent space in the new Energy Sciences Center, slated to open soon on the PNNL campus. He will move with nearly a dozen colleagues from his lab, along with three ultrahigh vacuum systems and other instruments crucial to his research.

Teaching, and learning a lesson about love for labs

It’s remarkable Chambers landed on the PNNL campus at all.

After graduating in 1978 from OSU with a PhD in physical chemistry, Chambers envisioned a career in academia. He took a job at George Fox University in Newberg, Oregon, as an assistant professor of chemistry and physics while also working as a visiting scientist at the Oregon Graduate Institute in Beaverton, Oregon. In 1982, he left the Northwest for a four-year stint teaching at Bethel University in St. Paul, Minnesota, and serving as a research professor at the University of Minnesota at Minneapolis.

But he felt a gravitational pull toward full-time research. He began exploring opportunities at national laboratories and in industry. At about the same time, Boeing was starting its High Technology Center (HTC) in Seattle to develop advanced aerospace electronics.  Chambers joined the new entity as a research scientist. While most of the HTC scientists sought breakthroughs in circuits and systems for Boeing’s space and defense sectors, Chambers worked in the materials group focused on fundamental science in support of these programs.

“It was a great job. And there were two projects I really enjoyed contributing to,” Chambers said. “One of them was high-performance solar cells for spacecraft. The other was computer circuits that could function in the space environment, shielded from cosmic radiation by an integral part of the device structure.”

But with the end of the Cold War in the late 1980s, the internal market for much of the HTC’s new technology dried up. The future of the HTC was in question. The director of the Materials and Devices Group pulled Chambers aside early in 1992, told him about the center’s fate, and suggested he start looking for another job.

Old contact opens new door

Earlier in 1991, Chambers met a PNNL scientist at a conference. It was John LaFemina, now PNNL’s executive director for performance management and chief risk officer.

“John said, ‘Hey, we're starting this new thing called the Environmental Molecular Sciences Laboratory. It's kind of a concept right now, but we're looking for somebody to head up a group to do oxide epitaxial film growth to make model mineral, catalyst, and sensor surfaces. Would you be interested?’”

At the time, Chambers was doing epitaxial film growth and interface science at Boeing as part of the company’s development of advanced electronic materials and devices. “PNNL wanted this kind of expertise for EMSL,” Chambers recalled, “but in the context of fundamental geochemical and catalytic interface science.”

Chambers politely declined. In early 1992, though, Chambers called LaFemina back and said, “‘Hey John, is that job still available?’ He said absolutely it is. And so I came across the mountains for an interview. About two months later, I went over for a second interview. On the day of my second interview, Boeing announced they were closing the High Technology Center. I was hired at PNNL shortly after that. That made for a pretty easy transition from Boeing to PNNL.”

Standing in his EMSL lab, Chambers leans over toward a stainless steel chamber and squints, peering into a circle-shaped window protruding from the chamber. He’s been in this lab, one of the first ones to be occupied in what was a brand-new Department of Energy Office of Science user facility, since January 1997.

“Take a look in there,” he said, gesturing to the tiny window.

Blue-tinted light illuminated a disk behind the 3-inch diameter glass viewport. On the disk was mounted a recently prepared specimen.

The chamber, called a molecular-beam epitaxial growth system, allows Chambers and his colleagues to grow ultrathin materials in a precise way in a high-vacuum environment.

“The very low pressure you find in there is comparable to what you find in outer space,” Chambers said. “It’s ultraclean. We go through a painstaking process to achieve this level of cleanliness. The reason for this is we’re making materials by generating beams of atoms and shooting them at a substrate and we don’t want impurities. The substrate acts as a foundation—the same function as the foundation for a house. The atoms land on the surface of the substrate and move around because the substrate is hot. They then form a new material, a crystalline film that grows in a highly controlled fashion, one atomic layer at a time. We don’t want impurity atoms in the film, and we would get them if we didn’t have an ultraclean environment.”

New materials—slowly, carefully

The goal is making new materials that have useful properties. “Electronic, optical, electrochemical, and magnetic properties are of interest. We do fundamental, basic research on new and novel materials,” Chambers said, noting that a new material typically takes many months to perfect. “For example, we’re quite interested in materials that can harvest sunlight to split water, to make a mixture of hydrogen and oxygen for combustible fuel.”

“Water is a great starting material because there’s lots of it. And sunlight is an abundant energy source. If you can combine the energy of the sun with water and get the water to break apart into hydrogen and oxygen molecules, you can make a very potent fuel mixture that has zero carbon footprint. That’s called water splitting. But it's a very difficult process to carry out efficiently. We're working on advanced materials consisting of layered structures of various oxides and at times conventional semiconductors that can harvest sunlight more efficiently than materials we now know about.”

Chambers is a global authority on the materials science of thin oxide films. In 2019, the AVS, a leading professional society for materials, interfaces, and processing science, gave Chambers its highest recognition, the Medard W. Welch Award. It’s named for the founder of the AVS, also known as the American Vacuum Society. The award, presented to recognize outstanding research, was given to Chambers for “pioneering contributions to the understanding, the origin, and influence of heterogeneities, defects, and disorder in complex oxide epitaxial films and heterostructures.” In 2004, he was also given the E.W. Mueller Award for Excellence in Surface Science by the University of Wisconsin. In addition to being a PNNL Lab Fellow, Chambers is also a Fellow of the AVS, the American Physical Society, and the American Association for the Advancement of Science.

Admiration of colleagues

Chambers has reached these achievement levels while setting his own high professional standards, said Peter Sushko, a PNNL staff scientist and sector manager who collaborates daily with Chambers.

“He pays acute attention to detail in a way that I would call pedantic—in a good way,” said Sushko, who met Chambers at a conference in Japan in 2003. “In science, it pays to be detail oriented. Scott pays attention. He goes deep. He challenges. He strives for precision in our work.”

That also means that while Chambers carefully scrutinizes his own findings before declaring them to be valid, he exacts the same level of scrutiny upon his colleagues, whether they like it or not.

“There is a saying, and Scott refers to it occasionally, that goes, ‘nothing resembles a new phenomenon more than a mistake,’” Sushko said. “Scott may look at findings that seem to be too good to be true and ask something like, ‘did you really make a new discovery, or was there some fundamental flaw in the experiments?’”

Another staff scientist on Chambers’ team, Steven Spurgeon, has also often seen his mentor’s principled approach to science. “He sets an example for us,” said Spurgeon, a materials scientist with a focus on electron microscopy.

Spurgeon said Chambers has created a specialty—and a culture—that have led to pivotal scientific advancements at the core of the Department of Energy’s mission.

“Scott has put together a lab where we’re exploring the interaction of atoms that give rise to properties used in important technologies, such as quantum computing, batteries, and solar cells,” Spurgeon said. “The lab is paving the way for the next generation of technology, creating novel materials a single atomic layer at a time, bringing together atoms in ways not found in nature.”

With Chambers poised to enter official retirement early next year but planning to continue participating in the research on a part-time basis, staff scientist Yingge Du will be taking over leadership and management of the molecular-beam epitaxy lab after it has made the move to the Energy Sciences Center. Du remembers how, more than a decade ago, he first became aware of Chambers.

Du was a graduate student at the University of Virginia. He was preparing to arrive at the PNNL campus in 2007 to start his postdoc work with the epitaxy instruments in EMSL. Before arriving, he checked the Wikipedia page for molecular-beam epitaxy. There, he found a description of the thin-film process. He also found a photograph of Chambers to illustrate the page.

“He’s on Wiki?” Du recalled thinking. “He must be a very big name.”

Chambers’ face is no longer part of the page, but Du is sticking with his first impression.

Du said there is one characteristic in particular he plans to borrow from Chambers and continue in his own lab leadership.

“Scott brings truth to the table,” said Du, who Chambers hired in 2010 as a PNNL staff scientist. “He doesn’t feel compelled to pursue every hot topic. He’s very straightforward. Sometimes that makes his peers in the research community uncomfortable by asking them the hard questions.”

Leaving a legacy

Chambers has authored or co-authored more than 300 peer-reviewed journal publications and more than 20 invited review articles and book chapters. He holds three patents and played a key role in the design of the molecular-beam epitaxial instruments that dominate the lab. Those accomplishments, though, are background music for the former orchestral clarinet player.

Chambers is in the game for the science, the basic science.

A computer screen sits next to an epitaxy instrument. The screen shows a live view of the inside of the vacuum chamber and an oscillating graph indicating the rate at which a film is growing in real time. Next to that screen, a large hardcover notebook, full of lined pages, lays open. The notebook displays handwritten notes about each phase of the deposition of a material. Other notebooks, filled with years of previous observations, lay nearby. Yes, he acknowledged, he could enter the observations directly into a computer. But there’s something tangibly engaging and convenient about handwritten information on a page.

“I’m a scientist who’s interested in fundamental properties of matter and deeper understanding of what makes materials tick,” Chambers said, pausing next to the epitaxy instrument. “My highest values are scientific rigor and integrity. We do our science carefully. We analyze our results with the highest level of scrutiny we can muster. We ask each other the hard questions, so an outsider reviewer won’t need to. We don’t overhype the results. We try not to leave any stone unturned in answering the questions we’re seeking to answer. We strive to be thorough and careful. And I’m OK being remembered as someone who’s understated. Better to have others herald your work more prominently than you do, rather than the other way around.”

 

 

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