Recent Progress in High-Pressure Brillouin Scattering: Olivine and Ice.

Zha, Chang‐Sheng; Mao, Ho‐kwang; Hemley, Russell J.; Duffy, Thomomas S.

doi:10.4131/jshpreview.7.739

Cited by 14 publications

(22 citation statements)

References 11 publications

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“…The precision of pressure measurement is __ 0.1 GPa along the entire experimental pressure range. Experimental data are summarized in were also used in a related Brillouin scattering study of MgO [Zha et al, 1998].…”

Section: Experimental Methodsmentioning

confidence: 99%

Quasi‐hydrostatic compression of magnesium oxide to 52 GPa: Implications for the pressure‐volume‐temperature equation of state

Speziale¹,

Zha²,

Duffy³

et al. 2001

J. Geophys. Res.

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413

325

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Section: Experimental Methodsmentioning

confidence: 99%

Quasi‐hydrostatic compression of magnesium oxide to 52 GPa: Implications for the pressure‐volume‐temperature equation of state

Speziale¹,

Zha²,

Duffy³

et al. 2001

J. Geophys. Res.

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413

325

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“…Lines represent theoretical V L 111 (P ) and V L 100 (P ) calculated for ice X: solid lines, earlier results of Journaux et al [3]; dashed lines, our ab initio calculations. The inset shows orientational distribution of V L in a single crystal of ice VII calculated using the C ij values at 40 GPa reported by Zha et al [30]. This distribution is equivalent to the statistical distribution of sound velocities in grains of a texture-free polycrystalline sample along a selected spatial direction and depicts the ideal shape of an averaged FDBS spectrum collected for such a sample.…”

Section: Figmentioning

confidence: 96%

“…Earlier data on V L (P) of ice VII and ice X at high pressures. Symbols represent experimental data from classical FDBS measurements: Open green triangles pointing left and right are V L 111 (P ) and V L 100 (P ), respectively, obtained for single crystals of ice VII by Shimizu et al [28]; open blue triangles pointing up and down are V L 111 (P ) and V L 100 (P ), respectively, calculated from the C ij (P ) dependencies reported by Zha et al [30]; diamonds and circles are longitudinal sound velocities V Lav (P ) derived from averaged FDBS spectra of polycrystalline ice samples by Polian and Grimsditch [26] and Ahart et al [29], respectively. The error bar shows the full width at half maximum (FWHM) of the FDBS peak at 77 GPa shown in the latter work.…”

Section: Figmentioning

confidence: 99%

“…Even though single crystals of ice VII disintegrate into polycrystalline domains upon further compression in a DAC [19,23,29,30], multiple resolved FDBS peaks with varying frequencies have been observed by scanning over such samples. This observation was explained by varying orientation of elastically anisotropic ice grains upon scanning and used to construct C ij (P ) of ice VII to 40 GPa by applying the so-called envelope method [29,30]: At each selected pressure, the FDBS peak giving the maximal V L is attributed to the crystallographic direction 111 while that giving the minimal V L to the direction 100 . However, at pressures below 10 GPa this approach led to a smaller value of A = 2.4 when compared with the single-crystal data in Ref.…”

Section: Figmentioning

confidence: 99%

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Longitudinal sound velocities, elastic anisotropy, and phase transition of high-pressure cubicH2Oice to 82 GPa

Kuriakose

Raetz

et al. 2017

Phys. Rev. B

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Water ice is a molecular solid whose behavior under compression reveals the interplay of covalent bonding in molecules and forces acting between them. This interplay determines high-pressure phase transitions, the elastic and plastic behavior of H 2 O ice, which are the properties needed for modeling the convection and internal structure of the giant planets and moons of the solar system as well as H 2 O-rich exoplanets. We investigated experimentally and theoretically elastic properties and phase transitions of cubic H 2 O ice at room temperature and high pressures between 10 and 82 GPa. The time-domain Brillouin scattering (TDBS) technique was used to measure longitudinal sound velocities (V L) in polycrystalline ice samples compressed in a diamond anvil cell. The high spatial resolution of the TDBS technique revealed variations of V L caused by elastic anisotropy, allowing us to reliably determine the fastest and the slowest sound velocity in a single crystal of cubic H 2 O ice and thus to evaluate existing equations of state. Pressure dependencies of the single-crystal elastic moduli C ij (P) of cubic H 2 O ice to 82 GPa have been obtained which indicate its hardness and brittleness. These results were compared with ab initio calculations. It is suggested that the transition from molecular ice VII to ionic ice X occurs at much higher pressures than proposed earlier, probably above 80 GPa.

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“…(30), and ice VII (40). The solid curve is the fitted result for MgO given by ϭ 0.18 ϩ 1.3 ϫ 10 Ϫ3 P ϩ 6.4 ϫ 10 Ϫ6 P 2 , where P is based on the new primary pressure scale.…”

Section: [4]mentioning

confidence: 99%

Elasticity of MgO and a primary pressure scale to 55 GPa

Zha

Mao

Hemley

2000

Proc. Natl. Acad. Sci. U.S.A.

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286

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We have studied the elasticity and pressure-density equation of state of MgO in diamond cells to 55 GPa and have doubled the previous pressure limit of accurate elasticity determinations for crystals. Integrating single-crystal velocity data from Brillouin scattering measurements and density data from polycrystalline x-ray diffraction, we obtained the three principal elastic tensor elements (C11, C12, and C44) and various secondary elasticity parameters, including single-crystal elastic anisotropy, Cauchy relation, aggregate sound velocities, and Poisson's ratio, as functions of pressure. The present study also provides a direct determination of pressure without recourse to any prior pressure standard, thus creating a primary pressure scale. The commonly used ruby fluorescence pressure scale has thus been improved to 1% accuracy by the new MgO scale. E lasticity, the fourth-rank tensor defining the strain of crystalline solids under stress (1), contains key parameters relating the microscopic bonding properties to the macroscopic mechanical behaviors of the solid under compression. The study of elasticity under high pressure has wide applications in fields ranging from crystal physics to seismology (2). Direct experimental measurements of the tensor elements, however, have previously been limited to 32 GPa (3)-above this pressure our knowledge has been derived from theoretical predictions, extrapolations of lower pressure data, or indirect measurements with assumed stress͞strain conditions (4). In the present study, we extend measurements of the elasticity of MgO, an archetypal oxide with the simple NaCl-type (B1) crystal structure, to 55 GPa at 300 K.MgO has been the subject of extensive theoretical and experimental investigations (5-17) that have revealed the fundamental bonding properties in this class of materials. With the wealth of available data, MgO is often used as a test ground for new theories, new experiments, and even as a pressure calibration standard for high-pressure, high-temperature experimentation (18,19). Moreover, MgO is a major component in the Earth's lower mantle (20,21), and knowledge of its high-pressure behavior is crucial for understanding deep Earth geophysics. The crystal structure and volume compression of polycrystalline MgO samples without pressure media have been studied with x-ray diffraction in diamond cells up to 227 GPa (7,22, 23). MgO in the B1 structure is stable over the entire pressure range. Nonhydrostatic conditions in these measurements, however, may introduce systematic deviations in pressure of up to 10% in the pressure-density equations of state (22-24). Ultrasonic and Brillouin scattering studies of single-crystal MgO (8,16,25) have yielded detailed information on its elastic tensor, anisotropy, and aggregate shear and bulk moduli, but have been limited to a maximum pressure of 18.6 GPa. Evidence for nonhydrostaticity has also been found in previous Brillouin scattering experiments at pressures exceeding the hydrostatic limits of the pressure media used in these s...

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Recent Progress in High-Pressure Brillouin Scattering: Olivine and Ice.

Cited by 14 publications

References 11 publications

Quasi‐hydrostatic compression of magnesium oxide to 52 GPa: Implications for the pressure‐volume‐temperature equation of state

Quasi‐hydrostatic compression of magnesium oxide to 52 GPa: Implications for the pressure‐volume‐temperature equation of state

Longitudinal sound velocities, elastic anisotropy, and phase transition of high-pressure cubicH2Oice to 82 GPa

Elasticity of MgO and a primary pressure scale to 55 GPa

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