March 3, 2014 12:20 PM

With measurements performed at the LERIX instrument at the High Pressure Collaborative Access Team (HP-CAT) beamline 16-ID, researchers have identified a structural phase change in V2O3 that occurs under great pressure, but without the usual metal-to-insulator transition. The interplay between crystal structure and electronic properties underlies almost every modern device, from pressure sensors to superconducting high speed trains.  More...

February 4, 2014 03:04 PM

Understanding the structural response of silicate melts to pressure and composition is crucial in earth and planetary sciences.  The degree of polymerization is a defining characteristic of silicate melt, and it affects the properties of silicate melts (e.g., viscosity, density).   Structural analyses on silicate melts (NaAlSi2O6-CaMgSi2O6 join) at high pressures (performed at HPCAT), in conjunction with molecular dynamics simulations, showed that structures of polymerized and depolymerized melts respond to pressure in distinct manner.  More...

January 31, 2014 04:20 PM

 Magnesite (MgCO3) is an important phase for the carbon cycle in and out of the Earth’s mantle. HPCAT experiments provide the first experimental evidence for synthesis of magnesite out of its oxide components (MgO and CO2). Magnesite formation was observed in situ using synchrotron X‑ray diffraction, coupled with laser-heated diamond-anvil cells, at pressures and temperatures of Earth’s mantle.    More....

January 22, 2014 06:09 PM

Anatase TiO2 is one of the most important energy materials but has poor electrical conductivity. The structural evolution and pressure-induced phase transitions in Nd-doped TiO2 nanomaterials have been studied by in situ synchrotron x-ray diffraction and Raman spectroscopy (both performed at HPCAT).  More....

November 26, 2013 07:55 PM

The Earth’spresent layered structure with a metallic core and an overlying silicate mantle would have required a mechanism to separate iron alloy from silicates. Percolation of liquid iron alloy moving through a solid silicate matrix has been proposed as a possible model for core formation.   More.....