Stability of numerous novel potassium chlorides at high pressure

Weiwei Zhang; Artem R. Oganov; Qiang Zhu; Sergey S. Lobanov; Elissaios Stavrou; Alexander F. Goncharov

doi:10.1038/srep26265

Stability of numerous novel potassium chlorides at high pressure

Weiwei Zhang^*, Artem R. Oganov, Qiang Zhu, Sergey S. Lobanov, Elissaios Stavrou, Alexander F. Goncharov

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

26 Scopus citations

Abstract

K-Cl is a simple system displaying all four main types of bonding, as it contains (i) metallic potassium, (ii) elemental chlorine made of covalently bonded Cl 2 molecules held together by van der Waals forces, and (iii) an archetypal ionic compound KCl. The charge balance rule, assigning classical charges of "+1" to K and "-1" to Cl, predicts that no compounds other than KCl are possible. However, our quantum-mechanical variable-composition evolutionary simulations predict an extremely complex phase diagram, with new thermodynamically stable compounds K₃Cl, K₂Cl, K₃Cl₂, K₄Cl₃, K₅Cl₄, K₃Cl₅, KCl₃ and KCl₇. Of particular interest are 2D-metallic homologs K_n+1 Cl_n, the presence of positively charged Cl atoms in KCl₇, and the predicted stability of KCl₃ already at nearly ambient pressures at zero Kelvin. We have synthesized cubic -KCl₃ at 40-70 GPa and trigonal -KCl₃ at 20-40 GPa in a laser-heated diamond anvil cell (DAC) at temperature exceeding 2000 K from KCl and Cl₂. These phases were identified using in situ synchrotron X-ray diffraction and Raman spectroscopy. Upon unloading to 10 GPa, -KCl₃ transforms to a yet unknown structure before final decomposition to KCl and Cl₂ at near-ambient conditions.

Original language	English
Article number	26265
Journal	Scientific Reports
Volume	6
DOIs	https://doi.org/10.1038/srep26265
State	Published - 23 May 2016
Externally published	Yes

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@article{fde2234dc6b34225a72d521619db3957,

title = "Stability of numerous novel potassium chlorides at high pressure",

abstract = "K-Cl is a simple system displaying all four main types of bonding, as it contains (i) metallic potassium, (ii) elemental chlorine made of covalently bonded Cl 2 molecules held together by van der Waals forces, and (iii) an archetypal ionic compound KCl. The charge balance rule, assigning classical charges of {"}+1{"} to K and {"}-1{"} to Cl, predicts that no compounds other than KCl are possible. However, our quantum-mechanical variable-composition evolutionary simulations predict an extremely complex phase diagram, with new thermodynamically stable compounds K3Cl, K2Cl, K3Cl2, K4Cl3, K5Cl4, K3Cl5, KCl3 and KCl7. Of particular interest are 2D-metallic homologs Kn+1 Cln, the presence of positively charged Cl atoms in KCl7, and the predicted stability of KCl3 already at nearly ambient pressures at zero Kelvin. We have synthesized cubic -KCl3 at 40-70 GPa and trigonal -KCl3 at 20-40 GPa in a laser-heated diamond anvil cell (DAC) at temperature exceeding 2000 K from KCl and Cl2. These phases were identified using in situ synchrotron X-ray diffraction and Raman spectroscopy. Upon unloading to 10 GPa, -KCl3 transforms to a yet unknown structure before final decomposition to KCl and Cl2 at near-ambient conditions.",

author = "Weiwei Zhang and Oganov, {Artem R.} and Qiang Zhu and Lobanov, {Sergey S.} and Elissaios Stavrou and Goncharov, {Alexander F.}",

note = "Funding Information: This work is funded by NSFC (Nos 11474355, 21403297, 61474142), Chinese Universities Scientific Fund (No. 2015LX002), DaBeiNong Young Scholars Research Plan, the Government of Russian Federation (No. 14.A12.31.0003) and Foreign Talents Introduction and Academic Exchange Program (No. B08040). A.F.G. acknowledges support from the Army Research Office and NSF-EAR. X-ray diffraction experiments were performed at GeoSoilEnviroCARS (Sector 13), Advanced Photon Source (APS), Argonne National Laboratory and Petra III, DESY, Hamburg, Germany. GeoSoilEnviroCARS is supported by the National Science Foundation-Earth Sciences (EAR-1128799) and Department of Energy-Geosciences (DE-FG02-94ER14466). The research leading to these results has received funding from NSFC (No. 21473211) and the European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement No. 312284. Use of the Advanced Photon Source was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. PETRA III at DESY is a member of the Helmholtz Association (HGF). S.S.L. was partly supported by the Ministry of Education and Science of Russian Federation (No. 14.B25.31.0032). Work of E.S. was performed under the auspices of the U. S. Department of Energy by Lawrence Livermore National Security, LLC under Contract DE-AC52-07NA27344.",

year = "2016",

month = may,

day = "23",

doi = "10.1038/srep26265",

language = "英语",

volume = "6",

journal = "Scientific Reports",

issn = "2045-2322",

publisher = "Nature Publishing Group",

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TY - JOUR

T1 - Stability of numerous novel potassium chlorides at high pressure

AU - Zhang, Weiwei

AU - Oganov, Artem R.

AU - Zhu, Qiang

AU - Lobanov, Sergey S.

AU - Stavrou, Elissaios

AU - Goncharov, Alexander F.

N1 - Funding Information: This work is funded by NSFC (Nos 11474355, 21403297, 61474142), Chinese Universities Scientific Fund (No. 2015LX002), DaBeiNong Young Scholars Research Plan, the Government of Russian Federation (No. 14.A12.31.0003) and Foreign Talents Introduction and Academic Exchange Program (No. B08040). A.F.G. acknowledges support from the Army Research Office and NSF-EAR. X-ray diffraction experiments were performed at GeoSoilEnviroCARS (Sector 13), Advanced Photon Source (APS), Argonne National Laboratory and Petra III, DESY, Hamburg, Germany. GeoSoilEnviroCARS is supported by the National Science Foundation-Earth Sciences (EAR-1128799) and Department of Energy-Geosciences (DE-FG02-94ER14466). The research leading to these results has received funding from NSFC (No. 21473211) and the European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement No. 312284. Use of the Advanced Photon Source was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. PETRA III at DESY is a member of the Helmholtz Association (HGF). S.S.L. was partly supported by the Ministry of Education and Science of Russian Federation (No. 14.B25.31.0032). Work of E.S. was performed under the auspices of the U. S. Department of Energy by Lawrence Livermore National Security, LLC under Contract DE-AC52-07NA27344.

PY - 2016/5/23

Y1 - 2016/5/23

N2 - K-Cl is a simple system displaying all four main types of bonding, as it contains (i) metallic potassium, (ii) elemental chlorine made of covalently bonded Cl 2 molecules held together by van der Waals forces, and (iii) an archetypal ionic compound KCl. The charge balance rule, assigning classical charges of "+1" to K and "-1" to Cl, predicts that no compounds other than KCl are possible. However, our quantum-mechanical variable-composition evolutionary simulations predict an extremely complex phase diagram, with new thermodynamically stable compounds K3Cl, K2Cl, K3Cl2, K4Cl3, K5Cl4, K3Cl5, KCl3 and KCl7. Of particular interest are 2D-metallic homologs Kn+1 Cln, the presence of positively charged Cl atoms in KCl7, and the predicted stability of KCl3 already at nearly ambient pressures at zero Kelvin. We have synthesized cubic -KCl3 at 40-70 GPa and trigonal -KCl3 at 20-40 GPa in a laser-heated diamond anvil cell (DAC) at temperature exceeding 2000 K from KCl and Cl2. These phases were identified using in situ synchrotron X-ray diffraction and Raman spectroscopy. Upon unloading to 10 GPa, -KCl3 transforms to a yet unknown structure before final decomposition to KCl and Cl2 at near-ambient conditions.

AB - K-Cl is a simple system displaying all four main types of bonding, as it contains (i) metallic potassium, (ii) elemental chlorine made of covalently bonded Cl 2 molecules held together by van der Waals forces, and (iii) an archetypal ionic compound KCl. The charge balance rule, assigning classical charges of "+1" to K and "-1" to Cl, predicts that no compounds other than KCl are possible. However, our quantum-mechanical variable-composition evolutionary simulations predict an extremely complex phase diagram, with new thermodynamically stable compounds K3Cl, K2Cl, K3Cl2, K4Cl3, K5Cl4, K3Cl5, KCl3 and KCl7. Of particular interest are 2D-metallic homologs Kn+1 Cln, the presence of positively charged Cl atoms in KCl7, and the predicted stability of KCl3 already at nearly ambient pressures at zero Kelvin. We have synthesized cubic -KCl3 at 40-70 GPa and trigonal -KCl3 at 20-40 GPa in a laser-heated diamond anvil cell (DAC) at temperature exceeding 2000 K from KCl and Cl2. These phases were identified using in situ synchrotron X-ray diffraction and Raman spectroscopy. Upon unloading to 10 GPa, -KCl3 transforms to a yet unknown structure before final decomposition to KCl and Cl2 at near-ambient conditions.

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U2 - 10.1038/srep26265

DO - 10.1038/srep26265

M3 - 文章

AN - SCOPUS:84970005638

SN - 2045-2322

VL - 6

JO - Scientific Reports

JF - Scientific Reports

M1 - 26265

ER -

Stability of numerous novel potassium chlorides at high pressure

Abstract

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