June 8, 2016 04:52 PM

Iron and oxygen are two of the most geochemically important elements on Earth. Recent experiments at HPCAT identified a highly stable, pyrite-structured iron oxide (FeO2) at 76 GPa and 1,800 K that holds an excessive amount of oxygen.  More...

May 5, 2016 06:37 PM

Applied pressure is a powerful tool for studying intermediate valent systems because their electronic states are sensitive to small changes in interatomic separation. Recent HPCAT experiments using resonant x-ray emission spectroscopy show that the pressure dependence of the f-electron occupancy in the Kondo insulator SmB6More...

May 4, 2016 02:34 PM

Near the Earth’s core-mantle boundary (CMB) there occur isolated regions characterized by anomalously high density and low seismic wave velocity.  A better understanding of the origin and evolution of ULVZs would play a crucial role in understanding the evolutionary history and planetary dynamics of the Earth as a whole.  Recent experiments at HPCAT explore the melting curve of the iron-carbon system.  More...

May 3, 2016 06:54 PM

The separation of iron metal from silicate to form Earth’s core represents a fundamental physical and chemical differentiation process in our planet’s history. A longstanding problem has been determining the minor element contribution to its predominately iron-nickel alloy. Recent HPCAT experiments using nuclear forward scattering technique show the effect of pressure on iron isotopic composition, which are found to vary according to the alloy tested (FeO, FeHx, or Fe3C versus pure Fe).   More...

May 1, 2016 06:31 PM

Depleted uranium and its alloys are important engineering materials due to their high density. Recent HPCAT experiments using ultrasonic interferometry have determined the elasticity, mechanical, and thermal properties of depleted uranium to 4.5 GPa. By combining X-ray radiographic, diffractive, and ultrasonic interferometric measurements of the sample, a pressure–volume curve and sound velocities have been determined.  More...