IUCr journals

Thermoelastic properties of magnesiowüstite, (Mg1-xFex)O: determination of the Anderson-Grüneisen parameter by time-of-flight neutron powder diffraction at simultaneous high pressures and temperatures

J. Appl. Cryst. (2008). 41, 886-896 (doi.org/10.1107/S0909049508029439)

[Rietveld plot] Rietveld refinement of a mixture of Fe (used to determine the pressure) and Mg0.8Fe0.2O at 4.9 GPa and 390 K.
Seismic tomography and geodynamical modelling are major techniques for studying the Earth's lower mantle. Both methods require knowledge of how the elastic properties of mantle constituents, such as magnesiowüstite [(Mg,Fe)O], vary with pressure, temperature and composition. The Anderson-Grüneisen parameter gives a measure of the rate of change of the bulk modulus with temperature, and the rate of change of the thermal expansion coefficient with pressure. We have used lattice parameter measurements by time-of-flight neutron powder diffraction at simultaneous high pressure and high temperature to determine this quantity.

I. G. Wood, L. Vocadlo, D. P. Dobson, G. D. Price, A. D. Fortes, F. J. Cooper, J. W. Neale, A. M. Walker, W. G. Marshall, M. G. Tucker, D. J. Francis, H. J. Stone and C. A. McCammon