Aggregate shear moduli of iron up to 90 GPa and 1100 K

We demonstrate that the mean-square atomic vibrations or Debye-Waller temperature factors of cubic (bce and fcc) and hcp-metals can be related to aggregate shear moduli at different pressures and temperatures. We show that high-quality powder X-ray diffraction data, collected in diamond anvil cells, provide sufficient information for Rietveld refinement and determination of temperature factors. For the first time, we have determined the shear modulus at pressures over 90 GPa and temperatures over 1000 K, using a new method based on a combination of thermal equation of state and measured mean-square atomic vibrations of Low-pressure cubic alpha-Fe and high-pressure epsilon-Fe phases. (C) 2000 Elsevier Science S.A. All rights reserved.