Kr environment in feldspathic glass and melt: A high pressure, high temperature X-ray absorption study

Crépisson, Céline; Sanloup, C.; Cormier, Laurent; Blanchard, Marc; Hudspeth, Jessica; Rosa, Angelika Dorothea; Mathon, O.; Irifune, Tetsuo

doi:10.1016/j.chemgeo.2018.07.008

Cited by 9 publications

(4 citation statements)

References 59 publications

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“…This distribution has been recently quantified in vitreous silica by neutron diffraction [55], the six-membered ring being the most prominent and having an inner diameter of 4.30 Å, consistent with the Xe-O bond length reported above. Krypton local environment in compressed melts, as investigated using x-ray absorption spectroscopy [56], is a shell of oxygen atoms located at 2.49 Å. This relatively short distance indicates some degree of covalency albeit less than for Xe-O bonds.…”

Section: Stuffed Amorphous Silicatesmentioning

confidence: 99%

“…However, the "missing Xe problem" requires a solution that only applies to Xe. Kr retention mechanism as a minor element has so far only been elucidated in compressed silicate melts [56], with the detection of Kr-O bonds having a lower degree of covalency than Xe-O bonds. Ar and Ne retention mechanisms will be very challenging to solve experimentally due to their lighter mass and consequent weak contribution to x-ray based signals.…”

Section: Future Directionsmentioning

confidence: 99%

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Noble Gas Reactivity in Planetary Interiors

Sanloup

2020

Front. Phys.

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While the field of noble gas reactivity essentially belongs to chemistry, Earth and planetary sciences have brought a different perspective to the field. Indeed, planetary interiors are natural high pressure (P) and high temperature (T) laboratories, where conditions exist where bonding of the heaviest noble gases may be induced thermodynamically through volume reduction (Le Châtelier's principle). Earth and planetary sciences besides generate numerous and precise observations such as the depletion of the terrestrial and martian atmospheres in xenon, pointing to the potential for Xe to be sequestered at depth, potentially induced by its reactivity. More generally, this paper will review the advances on noble gas reactivity at the extreme P-T conditions found within planetary interiors from experiments and theoretical investigations. This review will cover the synthesis of cage compounds, stoichiometric oxides and metals, and non-stoichiometric compounds where noble gases are only minor or trace elements but could be essential in solving some Earth and planetary puzzles. An apparent trend in noble gas reactivity with P emerges. In the case of Xe which is the most documented, metals are synthesized above 150 GPa, i.e., at terrestrial core conditions, stoichiometric Xe-oxides between 50 and 100 GPa, i.e., in the P-T range of the Earth's lower mantle, but Xe-O high energy bonds may also form under the modest pressures of the Earth's crust (<1 GPa) in non-stoichiometric compounds. Most planetary relevant noble gas compounds found are with xenon, with only a few predicted helium compounds, the latter having no or very little charge transfer between helium and neighboring atoms.

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Section: Stuffed Amorphous Silicatesmentioning

confidence: 99%

Section: Future Directionsmentioning

confidence: 99%

Noble Gas Reactivity in Planetary Interiors

Sanloup

2020

Front. Phys.

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“…Unlike for Xe, there is no report of P-induced oxidation for any other noble gas in crystalline silicates. Oxidation has only been reported for Kr in magmas 48 , with a Kr-O bond length at 2.5±0.1 Å too large to be accommodated by substitution of Kr to Si in the [SiO 4 ] -1 tetrahedra, but that can fit into the melt rings structure 49 . In early planetary stages, Kr bonding to oxygen only in magmas might have resulted in isotopically heavier magmas that eventually degassed before loss of the primary atmosphere, and in isotopically lighter crystals consistently with terrestrial Kr being depleted in heavy isotopes by 0.8‰ per a.m.u.…”

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confidence: 99%

Hadean isotopic fractionation of xenon retained in deep silicates

Igor¹,

Sanloup²,

Gilabert

et al. 2022

Nature

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“…This unexpected behaviour is underpinned by the P-induced reactivity of Xe inserts itself in the 6-membered-rings of the melt network, forming covalent bonds with the surrounding oxygens [2]. Such behaviour is only partly observed for Kr [3], while Br and I have different atomic environments [4].…”

mentioning

confidence: 99%