Stress-induced proton disorder in hydrous ringwoodite

Koch‐Müller, Monika; Speziale, S.; Deon, Fiorenza; Mrosko, Maria; Schade, U.

doi:10.1007/s00269-010-0383-2

Cited by 17 publications

(10 citation statements)

References 27 publications

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“…We observe a similar loss of absorption at 35 GPa in the ringwoodite OH stretching region as observed in Chamorro Pérez et al (2006) and Koch-Müller et al (2011). Portions of the sample attributed to the superhydrous B inclusions show clear OH absorption at 3440 and 3330 cm -1 at 35 GPa, with no significant narrowing (<5%) of the two OH bands during the cooling cycle to 5 K. These superhydrous B OH absorption bands shift upon room-temperature decompression to 3444 and 3349 cm -1 at 23 GPa, then ultimately to 3406 and 3349 cm -1 at 0 GPa, with dν/dP = 0.97 and -0.54 cm -1 /GPa, respectively, consistent with FTIR compression of superhydrous B to 15 GPa (Koch-Müller et al 2005).…”

Section: High-pressure Ftir Spectrasupporting

confidence: 87%

Hydrous ringwoodite to 5 K and 35 GPa: Multiple hydrogen bonding sites resolved with FTIR spectroscopy

Panero

Smyth

Pigott

et al. 2013

American Mineralogist

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Multiple substitution mechanisms for hydrogen in γ-(Mg,Fe) 2 SiO 4 , ringwoodite, lead to broad, overlapping, and difficult-to-interpret FTIR spectra. Through combined low-temperature, high-pressure synchrotron-based FTIR spectroscopy, the multiple bonding sites become evident, and can be traced as a function of temperature and compression. Multiple OH stretching bands can be resolved in iron-bearing and iron-free samples with 0.79-2.5(3) wt% H 2 O below 200 K at ambient pressure, with cooling to 5 K at 35 and 23 GPa resulting in the resolution of possibly as many as 5 OH stretching bands traceable at room temperature from 23 GPa down to 8 GPa. A distribution of defect mechanisms between o″ Mg +2(H · ) at 3100, 3270, and possibly 2654 cm -1 , o Si ‴′+4(H · ) at 3640 cm -1 , and Mg″ Si +2(H · ) at 2800 cm -1 can then be resolved. These multiple defect mechanisms can therefore explain the higher electrical and proton conductivity in ringwoodite when compared to wadsleyite, and therefore may be applied to resolve spatial variations in water storage in the Earth's transition zone.

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Section: High-pressure Ftir Spectrasupporting

confidence: 87%

Hydrous ringwoodite to 5 K and 35 GPa: Multiple hydrogen bonding sites resolved with FTIR spectroscopy

Panero

Smyth

Pigott

et al. 2013

American Mineralogist

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“…Always consult and cite the final, published document. See http:/www.minsocam.org or GeoscienceWorld Jacobsen et al 2005;Chamorro Pérez et al 2006;Koch-Müller et al 2011;Panero et al 2013;Yang et al 2014;Sakurai et al 2015). Thus, it may be inferred the local environments of hydrogen defects in clinopyroxene at high temperature and high pressure is the same as ambient conditions.…”

Section: Implications Hydrogen Speciation and Sites In The Clinopyroxmentioning

confidence: 99%

Nature of hydrogen defects in clinopyroxenes from room temperature up to 1000 °C: Implication for the preservation of hydrogen in the upper mantle and impact on electrical conductivity

Yang

Ingrin

Xia

et al. 2019

American Mineralogist

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Water incorporated as hydrogenated defects in mantle minerals can influence physical properties of the mantle. Knowledge of hydrogen defects at high temperatures (T) is fundamental to understand and quantify their influence on mantle physical properties. Clinopyroxene contributes significantly to the upper mantle water budget. Here, we investigate the behavior of hydrogen defects in ten natural clinopyroxene crystals at temperatures up to 1000 o C, using in situ and quenched experiments. The in situ high T Fourier transform infrared (FTIR) spectra indicate no proton transfer between point defects, but the local environments of hydrogen defects vary. Dehydration rates at 1000 o C of the six samples with different chemical compositions are calculated based on the quenched experiments. These rates are not only slightly site-specific, but also increase with Fe and tetrahedrally coordinated Al contents. Indeed, the Near-FTIR spectra suggest that the dehydration of the samples in this study involves oxidation of Fe 2+. For two diopsides with a mantle affinity, the diffusivity is about 10 −12 m 2 /s at 1000 °C. The results mainly have the following implications: (1) the different local environments of hydrogen defects between high T and low T may be responsible for the different mechanism of water impact on This is a preprint, the final version is subject to change, of the American Mineralogist (MSA) Cite as Authors (Year) Title. American Mineralogist, in press.

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“…The latter mechanism could perhaps be considered as a Snoek‐like relaxation but at high enough concentrations could become an order/disorder phenomenon. For example, external shear stress on hydrous ringwoodite induces a disordering reaction (Koch‐Müller et al . 2011), implying that there is significant coupling between strain and proton configuration.…”

Section: Phase Transitions Which Might Contribute To Anelastic Lossmentioning

confidence: 99%

Anelasticity maps for acoustic dissipation associated with phase transitions in minerals

Carpenter¹,

Zhang²

2011

Geophysical Journal International

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S U M M A R YAcoustic dissipation due to structural phase transitions in minerals could give rise to large seismic attenuation effects superimposed on the high temperature background contribution from dislocations and grain boundaries in the Earth. In addition to the possibility of a sharp peak actually at a transition point for both compressional and shear waves, significant attenuation might arise over wider temperature intervals due to the mobility of transformation twins or other defects associated with the transition. Attenuation due to structural phase transitions in quartz, pyroxenes, perovskites, stishovite and hollandite, or to spin state transitions of Fe 2+ in magnesiowüstite and perovskite and the hcp/bcc transition in iron-nickel (Fe-Ni) alloy, are reviewed from this perspective. To these can be added possible loss behaviour associated with reconstructive transitions which might occur by a ledge mechanism on topotactic interfaces (orthopyroxene/clinopyroxene, olivine/spinel and perovskite/postperovskite), with impurities (Snoek effect) or with mobility of protons. There are experimental difficulties associated with measuring dissipation effects in situ at simultaneous high pressures and temperatures, so reliance is currently placed on investigation of analogue phases such as LaCoO 3 for spinstate behaviour and LaAlO 3 for the dynamics of ferroelastic twin walls. Similarly, it is not possible to measure loss dynamics simultaneously at the low stresses and low frequencies that pertain in seismic waves, so reliance must be placed on combining different techniques, such as dynamic mechanical analysis (low frequency, relatively high stress) and resonant ultrasound spectroscopy (high frequency, low stress), to extrapolate acoustic loss behaviour over wide frequency, temperature and stress intervals. In this context 'anelasticity maps' provide a convenient means of representing different loss mechanisms. Contouring of the inverse mechanical quality factor, Q −1 , can be achieved if the appropriate constitutive laws are known. The overall approach is illustrated using the examples of spin-state transitions of Co 3+ in LaCoO 3 and twin mobility in single crystals of the rhombohedral phase of LaAlO 3 . Anelasticity maps of this type should give seismologists a clearer view of the characteristic patterns of seismic velocity and attenuation that could be used to detect (or rule out) the presence of particular phase transitions or loss behaviour in the core and mantle.

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Stress-induced proton disorder in hydrous ringwoodite

Cited by 17 publications

References 27 publications

Hydrous ringwoodite to 5 K and 35 GPa: Multiple hydrogen bonding sites resolved with FTIR spectroscopy

Hydrous ringwoodite to 5 K and 35 GPa: Multiple hydrogen bonding sites resolved with FTIR spectroscopy

Nature of hydrogen defects in clinopyroxenes from room temperature up to 1000 °C: Implication for the preservation of hydrogen in the upper mantle and impact on electrical conductivity

Anelasticity maps for acoustic dissipation associated with phase transitions in minerals

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