We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Novel High‐Pressure Potassium Chloride Monohydrate and Its Implications for Water‐Rich Planetary Bodies.
- Authors
Wei, Xinmiao; Zhou, Qiang; Li, Fangfei; Zhang, Caizi; Sun, Fuxing; Zhang, Zihan; Li, Ruiyu; Yu, Hongyu; Yan, Yalan; Li, Liang; Liermann, Hanns‐Peter; Speziale, Sergio; Li, Xinyang
- Abstract
Saline water is a common fluid on the Earth's surface and in ice planets. Potassium chloride (KCl) is a common salt and is expected to be a ubiquitous solute in salt water in the Universe; however, few studies investigated the behavior of KCl‐H2O system at high pressures and temperatures. In this study, powder and single‐crystal X‐ray diffraction (SC‐XRD), Raman and Brillouin scattering combined with diamond anvil cells were used to investigate the phase relation in the KCl‐H2O system for different KCl concentrations at 0–4 GPa and 298–405 K. The results of powder X‐ray diffraction and Raman scattering demonstrate that a novel KCl hydrate is formed when KCl aqueous solutions transform to solid ice‐VI and ice‐VII at high pressure. Simultaneously, the single‐crystal of KCl hydrate is synthesized from a supersaturated KCl solution at 298 K and 1.8 GPa. The structure is solved by SC‐XRD, indicating a KCl monohydrate with the P21/n space group is formed. We have verified the phase stability of KCl monohydrate by using Raman spectroscopy and density functional theory. Our results indicate that KCl monohydrate is a stable phase under pressure and temperature conditions between 1.6 and 2.4 GPa and 298–359 K. By considering the thermal profile and composition of icy moons, we hypothesize that the formation and decomposition of KCl monohydrate might induce mantle convection in these moons. Plain Language Summary: More and more evidence indicates that salt ions (Na+, Ca2+, Mg2+, K+, Cl−, and SO42− ${\text{SO}}_{4}^{2-}$, etc.) could be dissolved in water and ices of the Earth‐like planets and water‐rich planets. The dissolution of alkali‐ and alkaline earth chlorides and sulfates in water and the incorporation of salt ions in the solid phases of H2O ices have a significant effect on their chemical and physical properties. Potassium chloride (KCl) is a ubiquitous salt in the Universe, and we investigated the phase relationship of the KCl‐H2O system for different KCl concentrations at pressures of 0–4 GPa and temperatures of 298–405 K. We were able to produce a single crystal of KCl monohydrate by adding KCl into a KCl‐saturated solution and pressurizing the solution at 1.8 GPa and 298 K. Our findings reveal the existence of a novel KCl monohydrate phase with monoclinic structure, which remains stable within the pressure and temperature range of 1.6–2.4 GPa and 298–359 K. Considering the thermal profile and composition of icy moons, our results suggest that the stability of the KCl monohydrate phase at pressures of 1.6–2.4 GPa and temperatures of 298–359 K may drive mantle convection through its formation and decomposition. Key Points: A novel KCl monohydrate is synthesized in KCl‐H2O system at high pressuresStructure, phase stability, and density of KCl monohydrate are determined at high pressures and temperaturesKCl monohydrate formation and decomposition potentially drive mantle convection in icy moons
- Subjects
X-ray powder diffraction; BRILLOUIN scattering; DIFFRACTIVE scattering; RAMAN scattering; SURFACE of the earth; POTASSIUM chloride
- Publication
Journal of Geophysical Research. Planets, 2023, Vol 128, Issue 10, p1
- ISSN
2169-9097
- Publication type
Article
- DOI
10.1029/2022JE007622