16th APS Topical Conference on Shock Compression of Condensed Matter
Volume 54, Number 8
Sunday–Friday, June 28–July 3 2009;
Nashville, Tennessee
Session A1: Plenary Session I
7:50 AM–8:50 AM,
Monday, June 29, 2009
Room: Tennessee Ballroom C
Chair: William Anderson, Los Alamos National Laboratory
Abstract ID: BAPS.2009.SHOCK.A1.2
Abstract: A1.00002 : High Energy Density Extended Solids
8:00 AM–8:50 AM
Preview Abstract
Abstract
Author:
Choong-Shik Yoo
(Institute for Shock Physics and Department of Chemistry, Washington State University)
Application of high pressure significantly alters the interatomic
distance
and, thus, the nature of intermolecular interaction, chemical
bonding,
molecular configuration, crystal structure, and stability of
solid. With
modern advances in high-pressure technologies, it is feasible to
achieve a
large (often up to a several-fold) compression of lattice, at which
condition material can be easily forced into a new physical and
chemical
configuration. The high-pressure thus offers enhanced
opportunities to
discover new phases, both stable and metastable ones, and to tune
novel
properties in a wide-range of atomistic length scale,
substantially greater
than (often being several orders of) those achieved by other thermal
(varying temperatures) and chemical (varying composition or
making alloys)
means.
Over the past decade or two, a large number of new materials and
novel
phenomena have been discovered and predicted at extreme
pressure-temperature
conditions. Commonly observed under extreme conditions is the
transformation
of solids into more compact structures with itinerant electrons
such as
metallic and nonmetallic extended phases. Nonmolecular extended
solids,
particularly made of low Z elements such as hydrogen, carbon,
nitrogen,
oxygen, and fluorine, constitute a new class of high energy
density solids,
which can store a large sum of energy in their three-dimensional
network
structure ($\sim $ several eV/bond). Yet, a large cohesive energy
of singly
bonded (or sp3 hybridized) electrons gives rise to an extremely
stiff
lattice and novel electronic and optical properties. Broadly
speaking, these
molecular-to-nonmolecular transitions occur due to electron
delocalization
manifested as a rapid increase in electron kinetic energy at high
density,
but there are many outstanding questions as well regarding the
exact nature
of chemical bonding, phase stability, chemical mechanisms, and so
on. These
questions constitute fundamental chemistry unique to extreme
pressure-temperature conditions, which will be discussed in this
talk. Also
presented are the future directions of high-pressure materials
research in
an emerging/complementary phase and time scales of dynamic and
static high
pressures.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2009.SHOCK.A1.2