A new three-angle energy-dispersive diffractometer

Barnes, P.; Jupe, Andrew C.; Colston, Sally L.; Jacques, Simon D. M.; Grant, A.; Rathbone, T. C.; Miller, Mike; Clark, S. M.; Cernik, Robert J.

doi:10.1016/s0168-583x(98)00730-7

Cited by 40 publications

(23 citation statements)

References 10 publications

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“…The sample temperature was estimated from the measured temperature of the cooling block by applying Newton's law of cooling. A collimated beam of polychromatic x-rays passed through the sample and Bragg scattered x-rays were intercepted at fixed scattering angles by a bank of three energy-dispersive Ge detectors [18]. The sample holder was cooled from 48 to −15 • C over 172 min.…”

Section: Methodsmentioning

confidence: 99%

Sodium sulfate heptahydrate: direct observation of crystallization in a porous material

Hamilton

Hall

Pel³

2008

J. Phys. D: Appl. Phys.

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It is well known that sodium sulfate causes salt crystallization damage in building materials and rocks. However since the early 1900s the existence of the metastable heptahydrate has been largely forgotten and almost entirely overlooked in scientific publications on salt damage mechanics and on terrestrial and planetary geochemistry. We use hard synchrotron x-rays to detect the formation of this metastable heptahydrate on cooling a porous calcium silicate material saturated with sodium sulfate solution. The heptahydrate persists indefinitely and transforms to mirabilite only below 0 • C. At the transformation, which is rapid, the solution is highly supersaturated with respect to mirabilite. We estimate that crystallization of the heptahydrate and of mirabilite have associated Correns pressures of about 9 and 19 MPa, respectively, exceeding the tensile strength of building stones. We detect lattice strains in the salts from x-ray measurements consistent with these values.

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Section: Methodsmentioning

confidence: 99%

Sodium sulfate heptahydrate: direct observation of crystallization in a porous material

Hamilton

Hall

Pel³

2008

J. Phys. D: Appl. Phys.

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“…Because the oxygen volumes calculated were so different from the molecular dynamics, shock wave, and ISS values on which Figure 1a is based, we sought to improve our measurement procedures to either confirm or revise our initial efforts. First we devised a more comprehensive calibration procedure [ Walker et al , 2000] for the new three‐element energy‐dispersive detector on Station 16.4 SRS Daresbury [ Barnes et al , 1998]. Second, we devised more favorable sample illumination geometry for minimizing temperature gradient effects (Figure 3).…”

Section: Measurement Of Solid Phase Volumesmentioning

confidence: 99%

O₂ volumes at high pressure from KClO₄ decomposition: D″ as a siderophile element pump instead of a lid on the core

Walker

Clark

Cranswick

et al. 2002

Geochem Geophys Geosyst

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New measurements of the high‐pressure volume of oxygen make plausible old, controversial diamond anvil cell (DAC) observations of a high‐pressure reaction between liquid Fe and Fe‐bearing silicate in which FeO dissolved into liquid Fe. If the Earth's D″ layer between core and mantle is the waste product of this reaction proceeding forward with oxygen transfer to the core, then D″ would form an effective lid preventing escape of siderophile elements from the core. On the other hand, it is at least as plausible that the core is now oxygen saturated and that core cooling and internal crystallization drive this reaction backward with transfer of Fe‐ and O‐rich material out of the core into D″. The 186Os anomalies in some plume basalts are more consistent with this D″ as a siderophile element pump scenario than the D″ as‐lid scenario. Contributions of siderophile elements to the mantle from the core could assist in balancing the persistently enigmatic budget of these elements.

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“…Data were recorded on two beamlines: the angle-dispersive diffractometer 9.1 (Roberts et al, 1998) and on the energy-dispersive diffractometer 16.4 (Clark, 1996;Barnes et al, 1997). The choice of diffraction technique is important in determining the geometry of the measurement and the design of¯ow cells, as the detector angles and penetration of the beam vary considerably with photon energy.…”

Section: Instrumentmentioning

confidence: 99%

X-ray study of the orientational order of a concentrated dispersion of kaolinite under flow

et al. 2001

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Diffraction with high-energy X-rays is used to determine the orientational alignment of kaolinite particles dispersed in water as they¯ow down a pipe. Angle-dispersive and energy-dispersive diffraction methods are compared. Detailed studies of samples as thick as 1 cm were possible using energydispersive diffraction. A tomographic technique with the sample scanned and rotated in the beam allows maps of the alignment to be determined. The alignment across a pipe of rectangular section was determined. A strong effect caused by the walls was observed, the plate-like particles tending to lie parallel to the wall near the boundary of the pipe.

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A new three-angle energy-dispersive diffractometer

Cited by 40 publications

References 10 publications

Sodium sulfate heptahydrate: direct observation of crystallization in a porous material

Sodium sulfate heptahydrate: direct observation of crystallization in a porous material

O₂ volumes at high pressure from KClO₄ decomposition: D″ as a siderophile element pump instead of a lid on the core

X-ray study of the orientational order of a concentrated dispersion of kaolinite under flow

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A new three-angle energy-dispersive diffractometer

Cited by 40 publications

References 10 publications

Sodium sulfate heptahydrate: direct observation of crystallization in a porous material

Sodium sulfate heptahydrate: direct observation of crystallization in a porous material

O2 volumes at high pressure from KClO4 decomposition: D″ as a siderophile element pump instead of a lid on the core

X-ray study of the orientational order of a concentrated dispersion of kaolinite under flow

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O₂ volumes at high pressure from KClO₄ decomposition: D″ as a siderophile element pump instead of a lid on the core