A gigahertz ultrasonic interferometer for the diamond anvil cell and high-pressure elasticity of some iron-oxide minerals

Steven D. Jacobsen*, Hans J. Reichmann, Anastasia Kantor, Hartmut A. Spetzler

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingChapter

25 Scopus citations

Abstract

This chapter presents several major advances in gigahertz-ultrasonic interferometry having occurred during the last 2 years. A second-generation high-frequency acoustic interferometer has been developed for high-pressure and high-temperature elasticity measurements in the diamond anvil cell. The instrument measures single-crystal compressional and shear-wave travel times that are converted to sound velocities and elastic moduli for direct application to problems in geophysics. The second-order elastic constants (cij) of several iron-bearing oxide minerals have been measured under hydrostatic pressures to ∼10 GPa. Pressure-induced C44 mode softening is observed in magnetite (Fe3O4), wüstite (Fe0.95O) and in iron-rich magnesiowüstite-(Mg, Fe)O, indicating that strong magneto-elastic coupling is common among these iron-rich oxides well ahead of known structural phase transitions. The generation of shear-waves with near-optical wavelengths has been achieved using a P-to-S conversion, and S-waves have been transmitted into a diamond anvil cells (DAC) using a new high-pressure shear-wave buffer rod based on that principle. The sound velocities and elastic constants of high-pressure crystals synthesized in the multi-anvil press can now be measured with GHz-ultrasonic interferometry. The versatility of GHz-ultrasonic interferometry to work with all kinds of diamond cells and samples of any optical character holds exciting potential for future studies aimed at measuring elastic anisotropy in high-pressure silicates, oxides and metals in the 30-50 GPa range or higher with application to problems in geophysics and materials science. © 2005

Original languageEnglish (US)
Title of host publicationAdvances in High-Pressure Techniques for Geophysical Applications
PublisherElsevier.
Pages25-48
Number of pages24
ISBN (Print)9780444519795
DOIs
StatePublished - Dec 1 2005

ASJC Scopus subject areas

  • Earth and Planetary Sciences(all)

Fingerprint Dive into the research topics of 'A gigahertz ultrasonic interferometer for the diamond anvil cell and high-pressure elasticity of some iron-oxide minerals'. Together they form a unique fingerprint.

Cite this