Timothy Strobel subjects materials to high-pressures to understand chemical processes  and interactions, and to create new, advanced energy-related materials.

For instance, silicon is the second most abundant element in the Earth’s crust and a mainstay of the electronics industry. But normal silicon is not optimal for solar energy. In its conventional crystalline form, silicon is relatively inefficient at absorbing the wavelengths most prevalent in sunlight.  Strobel made a discovery that may turn things around.  Using the high-pressure techniques pioneered at Carnegie, he created a novel form of silicon with its atoms arranged in a cage-like structure. Unlike normal silicon, this new form has near-ideal properties for absorbing sunlight, and could potentially usher in an entirely new generation of solar cells.

Understanding the chemical reactions that can create tiny molecular cages that hold other “guest” molecules—structures called clathrates—is key to creating a new generation of electronic devices and possible energy materials.  Strobel and team are the first to use high-pressure synthesis to create a stable clathrate of sodium (Na) and silicon (Si)—the least understood system of the so-called group 14 clathrates. Strobel also created a new clathrate of hydrogen sulfide (H2S) and molecular hydrogen (H2). Both findings open the door for major advances in materials science.

In addition to these experiments, Strobel and team performed calculations to predict how the materials would behave. Calculations and experiments revealed that sodium clathrates are thermodynamically stable at high pressure. The consistency suggests that scientists can use theoretical calculations to predict new synthesis routes for other compounds.

In other work, a team including Strobel reported the synthesis of an ionic semiconductor Mg2C, under high-pressure, high-temperature conditions, which is fully recoverable to ambient conditions. Semiconductors are substances with electrical conductivity between insulators and metals used in electronic circuits.

 Strobel received his B.S. and Ph. D. from the Colorado School of Mines in 2004 and 2008 respectively. In 2008 he became a Carnegie postdoctoral fellow, where he became fascinated by high-pressure science. In 2010 he was appointed research scientist, then staff scientist in 2011. For more see the Strobel lab

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Carnegie Science, Carnegie Institution, Carnegie Institution for Science, National Science Review
November 13, 2017

Washington, DC— Reservoirs of oxygen-rich iron between the Earth’s core and mantle could have played a major role in Earth’s history, including the breakup of supercontinents, drastic changes in Earth’s atmospheric makeup, and the creation of life, according to recent work from an international research team published in National Science Review.

The team—which includes scientists from Carnegie, Stanford University, the Center for High Pressure Science and Technology Advanced Research in China, and the University of Chicago—probed the chemistry of iron and water under the extreme temperatures and pressures of the Earth’s core-mantle boundary.

When the action of plate

August 30, 2017

Washington, DC— A team of Carnegie high-pressure physicists have created a form of carbon that’s hard as diamond, but amorphous, meaning it lacks the large-scale structural repetition of a diamond’s crystalline structure. Their findings are reported in Nature Communications.

Carbon is an element of seemingly infinite possibilities, because the configuration of its electrons allows for numerous self-bonding combinations that give rise to a range of materials with varying properties.

For example, some forms of carbon, such as coal, are what’s called amorphous, meaning that they lack the long-range repetitive structure that makes up a crystal.

Other forms of carbon are

August 1, 2017

The Geophysical Laboratory’s Postdoctoral Associate Zachary Geballe has been honored with Carnegie’s seventh Postdoctoral Innovation and Excellence (PIE) Award. These prizes are made through nominations from the departments and are chosen by the Office of the President. Geballe, in Viktor Struzhkin’s lab, was awarded the prize for his scientific innovations and community service to the Broad Branch Road (BBR) campus.

Zack works on developing methods to measure the heat capacities of metals and silicates at high pressures. This work applies to developing new materials and studying the deep interiors of planets.   He developed a pioneering technique to measure heat in a diamond

Carnegie Science, Carnegie Institution, Carnegie Institution for Science, University of Bristol
July 13, 2017

Washington, DC— Experimental petrologist Michael Walter, currently head of the School of Earth Sciences at the University of Bristol, has been selected as the eighth director of Carnegie’s Geophysical Laboratory.  He will begin his directorship on April 1, 2018.  

Walter has been at Bristol since 2004 and began a five-year term as head of school in 2013. He received his PhD in geology and Earth science from the University of Texas, Dallas, and a Bachelor of Science in the same from the University of Nebraska, Omaha. Early in his career, Walter was a postdoctoral fellow at the Geophysical Laboratory, so his new role is a homecoming.

Walter’s recent research has focused on

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The High Pressure Collaborative Access Team (HPCAT) was established to advance cutting-edge, multidisciplinary, high-pressure science and technology using synchrotron radiation at the Advanced Photon Source (APS) of Argonne National Laboratory in Illinois.

The integrated HPCAT facility has established four operating beamlines in nine hutches An array of novel X-ray diffraction—imaging at tiny scales--and spectroscopic techniques to reveal chemistry,  has been integrated with high pressure and extreme temperature instrumentation.

With a multidisciplinary approach and multi-institution collaborations, the high-pressure program at the HPCAT has enabeld myriad scientific

CDAC is a multisite, interdisciplinary center headquartered at Carnegie to advance and perfect an extensive set of high pressure and temperature techniques and facilities, to perform studies on a broad range of materials in newly accessible pressure and temperature regimes, and to integrate and coordinate static, dynamic and theoretical results. The research objectives include making highly accurate measurements to understand the transitions of materials into different phases under the multimegabar pressure rang; determine the electronic and magnetic properties of solids and fluid to multimegabar pressures and elevated temperatures; to bridge the gap between static and dynamic

The Energy Frontier Research in Extreme Environments Center (EFree) was established to accelerate the discovery and synthesis of kinetically stabilized, energy-related materials using extreme conditions. Partners in this Carnegie-led center include world-leading groups in five universities—Caltech, Cornell, Penn State, Lehigh, and Colorado School of Mines—and will use facilities built and managed by the Geophysical Laboratory at Argonne, Brookhaven, and Oak Ridge National Laboratories. Nine Geophysical Laboratory scientists will participate in the effort, along with Russell Hemley as director and Tim Strobel as associate director.

To achieve their goal, EFree personnel synthesize

The Geophysical Laboratory has made important advances in the growth of diamond by chemical vapor deposition (CVD).  Methods have been developed to produce single-crystal diamond at low pressure having a broad range of properties.

Leopoldo Infante became the director of the Las Campanas Observatory on July 31, 2017.

Since 2009, Infante has been the founder and director of the Centre for Astro-Engineering at the Chilean university. He joined PUC as an assistant professor in 1990 and has been a full professor since 2006. He was one of the creators of PUC’s Department of Astronomy and Astrophysics, and served as its director from 2000 to 2006. He also established the Chilean Astronomical Society (SOCHIAS) and served as its president from 2009 to 2010.

Infante received his B.Sc. in physics at PUC. He then acquired a MSc. and Ph.D. in physics and astronomy from the University of Victoria in Canada.

Guillermo Blanc wants to understand the processes by which galaxies form and evolve over the course of the history of the universe. He studies local galaxies in the “present day” universe as well as very distant and therefore older galaxies to observe the early epochs of galaxy evolution. Blanc conducts a series of research projects on the properties of young and distant galaxies, the large-scale structure of the universe, the nature of Dark Energy—the mysterious repulsive force, the process of star formation at galactic scales, and the measurement of chemical abundances in galaxies.

To conduct this work, he takes a multi-wavelength approach including observations in the UV,

Peter van Keken studies the thermal and chemical evolution of the Earth. In particularly he looks at the causes and consequences of plate tectonics; element modeling of mantle convection,  and the dynamics of subduction zones--locations where one tectonic plate slides under another. He also studies mantle plumes; the integration of geodynamics with seismology; geochemistry and mineral physics. He uses parallel computing and scientific visualization in this work.

He received his BS and Ph D from the University of Utrecht in The Netherlands. Prior to joining Carnegie he was on the faculty of the University of Michigan.

Peter Driscoll studies the evolution of Earth’s core and magnetic field including magnetic pole reversal. Over the last 20 million or so years, the north and south magnetic poles on Earth have reversed about every 200,000, to 300,000 years and is now long overdue. He also investigates the Earth’s inner core structure; core-mantle coupling; tectonic-volatile cycling; orbital migration—how Earth’s orbit moves—and tidal dissipation—the dissipation of tidal forces between two closely orbiting bodies. He is also interested in planetary interiors, dynamos, upper planetary atmospheres and exoplanets—planets orbiting other stars. He uses large-scale numerical simulations in much of his research