Single-crystal elasticity of diopside to 14GPa by Brillouin scattering

Liqin Sang, Jay D. Bass

Research output: Contribution to journalArticle

Abstract

The single-crystal elastic moduli (Cij) of diopside have been measured up to 14GPa using Brillouin spectroscopy, from which the aggregate compressional and shear velocities, adiabatic bulk modulus, shear modulus, and their pressure derivatives were obtained. A least-squares fit of the velocity-pressure data to third-order finite strain equation yields KS'=4.8(2), G'=1.7(1) with ρ0=3.264(6)g/cm3, Ks=114.6(7)GPa and G=72.7(4)GPa. The current study provides the first high-pressure experimental values for the individual Cij's of diopside and extends the range of direct measurements on the shear modulus to higher pressure. From the single-crystal moduli, the acoustic anisotropy of diopside is calculated and found to be higher than that of other major mantle minerals such as olivine, orthopyroxene, or garnet. The high anisotropy of diopsidic pyroxene is solely responsible for the observed acoustic anisotropy of eclogitic rocks. In mantle rocks containing both olivine and clinopyroxene, such as lherzolites, the diopside component could either enhance or diminish the bulk acoustic anisotropy, depending on the relationship of preferred orientation of these phases.

Original languageEnglish (US)
Pages (from-to)75-79
Number of pages5
JournalPhysics of the Earth and Planetary Interiors
Volume228
DOIs
StatePublished - Mar 2014

Keywords

  • Brillouin spectroscopy
  • Clinopyroxene
  • Diopside
  • Elastic properties
  • High pressure
  • Single crystal

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Geophysics
  • Physics and Astronomy (miscellaneous)
  • Space and Planetary Science

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