May 22, 2018 12:13 PM

When compressed above megabar pressures (>100 GPa), glasses may undergo structural transitions into more densely packed networks that differ from those at ambient pressure. Inelastic x-ray scattering (IXS, or X-ray Raman scattering), which can probe core electron excitation from glasses in a diamond anvil cell (DAC), has enabled exploration of the pressure-induced changes in atomic configurations of elements in oxide glasses under extreme compression.  Using an enhanced capability at HPCAT, a research group measured IXS spectra for prototypical B2O3 glasses at high pressure up to 120 GPa.  More....

April 3, 2018 05:20 PM

Recent discoveries of several stable dense hydrous minerals at high pressure–temperature conditions have led to an important implication of a massive water reservoir in the Earth’s lower mantle. A research team used HPCAT facility and demonstrated that (Fe,Al)OOH can be stabilized in a hexagonal lattice at 107–136 GPa and 2,400 K.  More...

March 19, 2018 12:09 PM

Topological Kondo insulator possesses characteristics of both the strong electron correlations and the topological configurations, as shown in a mixed-valence material SmB6. YbB6 is a structural analog of SmB6, but remains controversial whether compressed YbB6 material is a topological insulator or a Kondo topological insulator. A research team used HPCAT facility and performed x-ray measurements on YbB6 samples. More...

March 19, 2018 12:43 PM

By engineering molecules with mechanically heterogeneous components with a compressible (‘soft’) mechanophore and incompressible (‘hard’) ligands, a research team has created ‘molecular anvils’, resulting in isotropic stress that leads to relative motions of the rigid ligands, anisotropically deforming the compressible mechanophore and activating bonds. More...

February 13, 2018 08:07 PM

At temperatures (<319 K or <46 oC) where life is sustained, water is an abnormal liquid, having a number of anomalous properties.  It has been widely accepted that water’s anomalies are not a result of simple thermal fluctuation, but are connected to the formation of various structural aggregates in the hydrogen bonding network. To understand water’s anomalous behavior, a two-liquid model with a high-density liquid (HDL) and a low-density liquid (LDL) has been proposed from theoretical simulations. However, it has been experimentally challenging to probe the region of the phase diagram of H2O, often referred to as water’s no man’s land, where the LDL phase is expected to occur. A team at HPCAT overcame the experimental challenge by adopting a new kinetic pathway to access the region of LDL via decompression of a high-pressure crystal.  More...