Equation of state, elasticity, and shear strength of pyrite under high pressure

S. Merkel, A. P. Jephcoat, J. Shu, H. K. Mao, P. Gillet, R. J. Hemley

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    51 Citations (Scopus)


    Physical properties including the equation of state, elasticity, and shear strength of pyrite have been measured by a series of X-ray diffraction in diamondanvil anvil cells at pressures up to 50 GPa. A Birch-Murnaghan equation of state fit to the quasihydrostatic pressure-volume data obtained from laboratory X-ray source/film techniques yieilds a quasihydrostatic bulk modulus KOT = 133.5 (±5.2) GPa and bulk modulus first pressure derivative K'OT = 5.73 (±0.58). The apparrent equation of state is found to be strongly dependent on the stress conditions in the sample. The stress dependency of the high-pressure properties is examined with anisotropic elasticity theory from subsequent measurements of energy-dispersive radial diffraction experiments in the diamond-anvil cell. The calculated values of KOT depend largely upon the angle Ψ between the diffracting plane normal and the maximum stress axis. The uniaxial stress component in the sample, t = σ3 - σ1, varies with pressure as t = -3.11 + 0.43P between 10 and 30 GPa. The pressure derivatives of the elastic moduli dC11/dP = 5.76 (±0.15), dC12/dP = 1.41 (±0.11) and dC44/dP = 1.92 (±0.06) are obtained from the diffraction data assuming previously reported zeropressure ultrasonic data (C11 = 382 GPa, C12 = 31 GPa, and C44 = 109 GPa).

    Original languageEnglish
    Pages (from-to)1-9
    Number of pages9
    JournalPhysics and Chemistry of Minerals
    Issue number1
    Publication statusPublished - 2002


    • Elasticity
    • High pressure
    • Pyrite
    • Radial diffraction
    • Shear strength

    ASJC Scopus subject areas

    • Materials Science(all)
    • Geochemistry and Petrology


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