Abstract
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 language | English |
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Pages (from-to) | 1-9 |
Number of pages | 9 |
Journal | Physics and Chemistry of Minerals |
Volume | 29 |
Issue number | 1 |
DOIs | |
Publication status | Published - 2002 |
Keywords
- Elasticity
- High pressure
- Pyrite
- Radial diffraction
- Shear strength
ASJC Scopus subject areas
- Materials Science(all)
- Geochemistry and Petrology