at the Advanced Photon Source

Recent HPCAT Science Highlights

A team of scientists from the Condensed Matter Section, Physics Division, of LLNL and HPCAT at the Advanced Photon Source have investigated the response of the heavy rare-earth metal dysprosium under static compression in a soft pressure medium up to 182 GPa. In this study, both the pressure-volume relationship and the lattice parameter response of pure dysprosium metal was explored. The lattice parameters of each of the high-pressure polymorphs showed an anisotropic response to compression, as well as turning points in the anisotropy, which can be attributed to an… more

Atoms are commonly thought of as being round. New CDAC-funded experimental work by a team from UC Berkeley, Northwestern University, and HPCAT, Argonne National Laboratory, reports that pressure causes iron atoms to change shape deep inside our planet, however. This shapeshift alters the physical and chemical properties of crystals at depth, influencing the way Earth has evolved over its multi-billion-year history.

The high pressures of Earth's interior can be reproduced in laboratory experiments that squeeze minerals samples between the tips… more

Understanding the phase behavior of H2O is essential in geoscience, extreme biology, biological imaging, chemistry, and physics. High-density amorphous (HDA) phase of H2O is of particular importance due to its extensive application in preserving biological samples for imaging at cryogenic temperatures. In this collaborative research project, the scientists confirmed the formation of ice HDA at room temperature while included grains of crystalline ice VI. Their study revealed that neither of the two common imaging techniques including: X-ray diffraction (XRD) and Raman… more

Magnetic topological systems promise great potential applications in future dissipationless electronics due to their interplay of magnetism and topological quantum states. Since the discovery of the first intrinsic topological magnet MnBi2Te4, much effort has been placed in a series of Eu-based compounds for the rich phases such as strong local moment, valence fluctuation, and Kondo physics. A recently published work investigated the pressure tuning of magnetism, valence, crystal lattice, and topological state in a topological magnet EuSn2P2 under high… more

Astronomers have discovered thousands of planets orbiting other stars. Many of these planets are rocky like Earth, but considerably bigger. Researchers wonder if these “Super Earths” could support life. One of the requirements for life as we know it is plate tectonics, the slow churning of a planet’s interior that renews the surface, regulates the carbon cycle, and keeps liquid water available. Now, researchers have used the U.S. Department of Energy's Advanced Photon Source (APS) to understand how common silicate minerals would behave under the incredible pressures… more

A recently published work that combines molecular dynamics simulations, crystallographic theory generalized for strained crystals, and in-situ real-time Laue x-ray diffraction, reveals unprecedented nanostructure evolution during pressure-induced Si-I→Si-II phase transformation. The research effort was led by a long-time HPCAT user Professor V. Levitas, (Anson Marston Distinguished Professor in Engineering/Vance Coffman Faculty Chair Professor in Aerospace Engineering at ISU and staff member at Ames National Laboratory) and his former Ph.D. student Hao Chen (now a… more

A recent study published in the Journal of Applied Physics reports on the determination of the yield strength of tantalum to multi-megabar pressures. The work was a collaborative effort, led by student Christopher Perreault from UAB Professor Yogesh Vohra's SSAA partner group, with contributions from Lowell Miyagi and Sam Couper from the University of Utah CDAC partner group, and Larissa Huston, a postdoc from LANL in Blake Sturtevant's Tri-Lab partner group. A primary contribution of this work was the cross-validation of two independent methods for… more

The magma ocean stage in planetary formation is where most or all of a planetary body is molten, allowing for the separation of minerals and ultimately the formation of the silicate mantle as it cools. Physical properties of the silicate melt, such as viscosity, control the crystallization process where less viscous liquids allow for more separation of minerals into distinct compositional layers within the magma body. In order to understand the compositionally diverse surface of Mercury, the resulting interior structure formed from the magma ocean stage needed to be… more