Shpyrko receives APS organization's Young Investigator Award

For his thesis work, Shpyrko resolved a long-standing controversy on whether atomic layering is unique to liquid metals. He used x-ray surface scattering techniques to compare the surface structure in high-surface-tension liquid metals with the surface structure in low-surface-tension alkali metals and nonmetallic liquids. The results showed layering in alkali metals but no layering in water. The observation indicates that layering is unique to metallic liquids and it arises from electronic properties rather than high surface tension.

Shpyrko has continued to study the surface properties of liquid metals, working in particular with gold silicide (AuSi), a solder used in nanoscale circuitry. In contrast to the previously observed behavior of other liquid alloys and pure liquid metals, a nondilute liquid eutectic gold-silicon alloy (Au82Si18) developed both a crystallized alloy “skin” and an ordered structure extending several atomic layers into the bulk.

The “skin” remained an alloy, rather than segregating to a pure metal as in other liquid alloys. The results are important because properties at the nanoscale, including the effectiveness of AuSi as a nanoscale solder, are expected to depend heavily on surface effects. Located at Argonne, the APS is a national synchrotron x-ray research facility funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences. The APS provides the brightest x-ray beams in the Western Hemisphere to more than 5,000 scientists worldwide.

Argonne National Laboratory brings the world’s brightest scientists and engineers together to find exciting and creative new solutions to pressing national problems in science and technology. The nation’s first national laboratory, Argonne conducts leading-edge basic and applied scientific research in virtually every scientific discipline. Argonne researchers work closely with researchers from hundreds of companies, universities, and federal, state and municipal agencies to help them solve their specific problems, advance America’s scientific leadership and prepare the nation for a better future. With employees from more than 60 nations, Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy's Office of Science.