Emeritus professor named American Ceramic Society Fellow

Nathan Newman is among only 20 of his peers to be named a 2023 American Ceramic Society Fellow.

The emeritus professor of materials science and engineering in the Ira A. Fulton Schools of Engineering at Arizona State University embarked on his long path in the study of ceramics soon after earning a doctoral degree from Stanford University in 1987. At that time, he joined a startup venture to commercialize products based on a then-recently discovered high-temperature superconductor.

Despite the hype about the technology, the expectation that it would revolutionize electronic devices, from computers to power generation, never materialized.

“Our company, Conductus Inc., had targeted a large number of microelectronic uses, from digital processing for computers to ultrasensitive detectors for magnetic field and far infrared radiation,” Newman says. “They did not turn out to be marketable. However, while developing these devices, I had uncovered for the first time that the material I made was about three orders of magnitude lower loss in the microwave region than conventional materials.”

From this discovery, Newman went on to lead the effort that resulted in an important breakthrough for improved cell phone technology. The Conductus company’s main and only product — cell phone base station filters — was based on his invention.

“I actually left the company a few years after my discovery,” Newman says. “I felt that I made my contribution to that technology and wanted to focus more on basic research than development.”

While at Conductus, Newman found that, once optimized, the performance of the superconductor microwave devices were no longer dominated by the superconductor itself, but by the dielectrics. He wanted to better understand what caused this performance-limiting loss at high frequency in microwave dielectrics.

“I realized that this was either wrong or an incomplete solution because the internal atom’s vibrations have too high an energy to explain much of the data,” Newman says. “I continued to wonder how I could solve this significant problem. After coming to ASU and waiting for the opportunity, I had an idea. My research team modified our methods so that we could directly measure the microwave loss in the dielectrics, and we changed operating conditions.”

The group’s initial work clearly demonstrated that the losses they observed at low temperature could be decreased by almost 99% by applying a magnetic field. Atomic vibrations don’t have strong magnetic interactions.

“Instead, we were able to show that the very, very small magnetic movement of an electron, called its spin, was absorbing the energy by undergoing a spin-flip by changing its direction from down to up,” Newman says. “So, under the conditions that we were measuring, the high-frequency losses were from spin excitations after all and not the internal atom’s vibrations. Also, we were able to use high magnetic fields to suppress this source of loss, and now we could accurately measure any background losses.”

By looking at the temperature dependence, Newman and his team were able to show that the electron system was also involved over the entire temperature range.

Newman joined the American Ceramic Society almost 10 years ago so he could share these research results with the society and learn more about the subject.

“Since the advanced techniques that I learned from the semiconductor and superconductor field were not commonly used in their work and the conclusions were diametrically opposite to the field’s earlier conclusions, it took some time for our work to be understood and, to my delight, eventually welcomed,” he says.

Newman and his research team encountered some strong opposition to their new ideas, but they were eventually — sometimes grudgingly — accepted across the field.  .

“Because of the initial apprehension about the work, I felt even more honored that the American Ceramic Society would elevate my status to the fellow grade,” Newman says. “Of course, this recognition should be shared with my research team, including Lingato Liu, Shaojun Liu, Richard Hanley, Shengke Zhang, Siddhesh Gajare, Brett Strawbridge and Rakesh Singh, among others.”

The ceramics field is a much smaller basic research community than the semiconductor and superconductor community in which Newman usually works, and the area of ceramics he was working in was not considered a “hot field for basic research” he says.

“Initially our presentations were given to very small audiences,” Newman says. “Nevertheless, I was proud that my research group was able to answer this important fundamental question.”

Newman has had an illustrious career, earning a multitude of honors that include being named a fellow of the National Academy of Inventors in 2018, a fellow of the Institute of Electrical and Electronics Engineers in 2014, and a fellow of the American Physical Society in 2006. He is also a member of the European Union Academy of Sciences.

In the American Ceramic Society, fellow designation recognizes members who have distinguished themselves through outstanding contributions to the ceramic arts or sciences, broad and productive scholarship in ceramic science and technology, notable achievement in the ceramic industry and outstanding service to the society.

“I am most impressed that he has made significant contributions to many scientific and engineering fields,” says Terry Alford, a professor of materials science and interim director of the School for Engineering of Matter, Transport and Energy, part of the Fulton Schools.

“His group’s publication in the prestigious journal Physical Review Letters, followed by a series of groundbreaking papers, provided a new and deep understanding of the mechanism of microwave loss in practical microwave ceramic materials,” Alford says. “This and contributions in developing a solid fundamental knowledge of the properties of high-temperature superconductors and wide bandgap materials also contributed to receiving this high honor.”