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High Pressure

High pressure science and technology has been a major thrust area at the Geophysical Laboratory since the founding of the department.  The Laboratory continues to develop and explore the field of extreme environments.

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. Video- "Growing Synthetic Diamonds"

Researchers studying the Earth's core have found that neither the liquid outer core nor the solid inner core is as dense as would be expected if the core were pure iron. Lighter elements must be present. But which ones? Melted samples are subjected to pressures up to 250,000 atmospheres.

Scientists at the Geophysical Laboratory use the dedicated facilities of the Los Alamos and Oak Ridge National Laboratories for the study of neutron scattering of condensed matter.

 

A broad range of optical spectroscopy techniques are used by scientists at the Geophysical Laboratory studying high-pressure phenomena. These techniques include absorption, reflectivity, and emission spectra over a wide spectral range (240-16,000 nm), infrared absorption spectroscopy, and Raman spectroscopy -- These techniques can be used at combined high pressures and variable temperatures from cryogenic to laser heating conditions.

Scientists run hydrothermal organic chemistry experiments at temperatures ranging from 50 up to 250 °C and at pressures from 2-3 MPa up to 400 MPa.

 

NEW  Postdoc with optics and laser expertise will work as part of Energy Frontier Research in Extreme Environments Center at the Geophysical Labora

Probing minute samples at ultrahigh pressures requires high-energy beams from synchrotrons such as the Advanced Photon Source (APS) at Argonne National Laboratory. Geophysical Laborator yscientists have remained at the forefront of developing these new analytical tools.

High Pressure News

 

Washington, D.C., 4 February 2014—New research conducted by the Geophysical Laboratory's Viktor Struzhkin and team shows that a remarkable defect in synthetic diamond produced by chemical vapor deposition allows researchers to measure, witness, and potentially manipulate electrons in a manner that could lead to new “quantum technology” for information processing. 

Washington, D.C., 12 September 2013—New research from a team led by the Geophysical Laboratory's Alexander Goncharov hones in on the hydrocarbon methane (CH4), which is one of the most abundant molecules in the universe. 

Washington, D.C., 10 September 2013 -- A research team from the Geophysical Laboratory has reported the synthesis of an ionic semiconductor, Mg2C, under high-pressure, high-temperature conditions, which is fully recoverable to ambient conditions. In Mg2C, carbon becomes an anion with an extremely negative charge of 4e-.

Washington, D.C., 19 June 2013--Using novel high-pressure x-ray techniques, Geophysical Laboratory scientists have obtained the very first single-crystal structure of (Mg,Fe)SiO3 postperovskite phase under high pressure corresponding to the condition in the Earth’s D′′ layer.

Presentations

Russell J. Hemley "High-Pressure Geoscience: New Tools and Expanding Outreach", Workshop on Long Range Plans for High Pressure earth Sciences (Tempe, AZ, March 2-4, 2009).

Russell J. Hemley "Hydrogen, SUSSP 2008: High Pressure Physics", Scottish Universities Summer School in Physics No. 63 (Isle of Skye, Scottland, May 26-June 6, 2008).

Russell J. Hemley "New Light on Materials under Extreme Conditions: Synchrotron Radiation and High Pressure", ICTP (Trieste, November, 2006).

Russell J. Hemley "Overview of New Developments and Future Prospects in High Pressure Research ", Minerva School (Ein Guedi, March, 2006).