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Title: Thermal equation of state and thermodynamic Grüneisen parameter of beryllium metal

We conducted in-situ high-pressure synchrotron x-ray experiments on beryllium metal at pressures up to 7.9 GPa and temperatures up to 1373 K. A complete pressure (P)–volume (V)–temperature (T) equation of state (EOS) is determined based on the experiment, which includes temperature derivatives of elastic bulk modulus (at both constant pressure and constant volume) and pressure dependence of thermal expansivity. From this EOS, we calculate thermal pressure, heat capacity at constant volume, and thermodynamic Grüneisen parameter as a function of temperature. Above ∼600 K, our results show notable deviation from theoretical predictions using the quasiharmonic and local-density approximations, indicating that the free energy calculations need to be further improved within the current scheme of approximations.
Authors:
;  [1] ;  [2] ; ;  [3]
  1. Los Alamos Neutron Science Center, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
  2. Dynamic and Energetic Materials Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
  3. High Pressure Science and Engineering Center and Department of Physics and Astronomy, University of Nevada, Las Vegas, Nevada 89154 (United States)
Publication Date:
OSTI Identifier:
22257807
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 114; Journal Issue: 17; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; BERYLLIUM; EQUATIONS OF STATE; FREE ENERGY; PRESSURE DEPENDENCE; SPECIFIC HEAT; SYNCHROTRONS; TEMPERATURE DEPENDENCE