Approaches to constrain single-crystal elastic properties from Brillouin scattering of polycrystalline samples

Abstract

We have performed combined high pressure Brillouin scattering and X-ray diffraction of polycrystalline samples of MgO and of argon. We are able to reproduce the measured spatial dispersion of acoustic velocities and put constraints on the full elastic tensor by combining the texture, the density that we determine in situ and available elastic constants. The new approach of simultaneously determining density, preferred orientation and spatial dispersion of acoustic velocity of polycrystals promises to be a viable method to extract information on single-crystal (anisotropic) elastic properties of materials compressed to pressures at which single crystals cannot be preserved.

Keywords:

• Brillouin scattering
• high pressure
• polycrystalline samples
• acoustic velocity
• diamond anvil cell

Acknowledgements

The authors thank Z. Geballe and H.J. Reichmann for useful discussions, two anonymous reviewers for their thoughtful and useful comments, Z. Konôpkova and W. Morgenroth for technical help. H. Marquardt is supported by the DFG (SP 1216 $ / $ 3-1) within the SPP1236 ‘Synthesis, in situ characterization and quantum mechanical modeling of Earth materials, oxides, carbides and nitrides at extremely high pressures and temperatures’. Parts of the experiments were conducted in the framework of the Extreme Conditions Science Infrastructure of PETRA III at DESY.

Notes

^†This contribution is part of the final report summarizing the results of the DFG-priority project SPP1236, which was funded by the Deutsche Forschungsgemeinschaft from 2006 to 2013.