Pressure-Induced Superconductivity and Flattened Se6 Rings in the Wide Band Gap Semiconductor Cu2I2Se6

Weizhao Cai; Wenwen Lin; Long Hua Li; Christos D. Malliakas; Rong Zhang; Matthew Groesbeck; Jin Ke Bao; Dongzhou Zhang; Eran Sterer; Mercouri G. Kanatzidis; Shanti Deemyad

doi:10.1021/jacs.9b06794

Pressure-Induced Superconductivity and Flattened Se₆ Rings in the Wide Band Gap Semiconductor Cu₂I₂Se₆

Weizhao Cai, Wenwen Lin, Long Hua Li, Christos D. Malliakas, Rong Zhang, Matthew Groesbeck, Jin Ke Bao, Dongzhou Zhang, Eran Sterer, Mercouri G. Kanatzidis, Shanti Deemyad^*

^*Corresponding author for this work

Chemistry

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

9 Scopus citations

Abstract

The two major classes of unconventional superconductors, cuprates and Fe-based superconductors, have magnetic parent compounds, are layered, and generally feature square-lattice symmetry. We report the discovery of pressure-induced superconductivity in a nonmagnetic and wide band gap 1.95 eV semiconductor, Cu₂I₂Se₆, with a unique anisotropic structure composed of two types of distinct molecules: Se₆ rings and Cu₂I₂ dimers, which are linked in a three-dimensional framework. Cu₂I₂Se₆ exhibits a concurrent pressure-induced metallization and superconductivity at â¼21.0 GPa with critical temperature (T_c) of â¼2.8 K. The T_c monotonically increases within the range of our study reaching â¼9.0 K around 41.0 GPa. These observations coincide with unprecedented chair-to-planar conformational changes of Se₆ rings, an abrupt decrease along the c-axis, and negative compression within the ab plane during the phase transition. DFT calculations demonstrate that the flattened Se₆ rings within the CuSe layer create a high density of states at the Fermi level. The unique structural features of Cu₂I₂Se₆ imply that superconductivity may emerge in anisotropic Cu-containing materials without square-lattice geometry and magnetic order in the parent compound.

Original language	English (US)
Pages (from-to)	15174-15182
Number of pages	9
Journal	Journal of the American Chemical Society
Volume	141
Issue number	38
DOIs	https://doi.org/10.1021/jacs.9b06794
State	Published - Sep 25 2019

ASJC Scopus subject areas

Catalysis
Chemistry(all)
Biochemistry
Colloid and Surface Chemistry

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10.1021/jacs.9b06794

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Cai, W., Lin, W., Li, L. H., Malliakas, C. D., Zhang, R., Groesbeck, M., Bao, J. K., Zhang, D., Sterer, E., Kanatzidis, M. G., & Deemyad, S. (2019). Pressure-Induced Superconductivity and Flattened Se₆ Rings in the Wide Band Gap Semiconductor Cu₂I₂Se₆ Journal of the American Chemical Society, 141(38), 15174-15182. https://doi.org/10.1021/jacs.9b06794

@article{84a79554e90e437fbb475b187d135841,

title = "Pressure-Induced Superconductivity and Flattened Se6 Rings in the Wide Band Gap Semiconductor Cu2I2Se6 ",

abstract = "The two major classes of unconventional superconductors, cuprates and Fe-based superconductors, have magnetic parent compounds, are layered, and generally feature square-lattice symmetry. We report the discovery of pressure-induced superconductivity in a nonmagnetic and wide band gap 1.95 eV semiconductor, Cu2I2Se6, with a unique anisotropic structure composed of two types of distinct molecules: Se6 rings and Cu2I2 dimers, which are linked in a three-dimensional framework. Cu2I2Se6 exhibits a concurrent pressure-induced metallization and superconductivity at {\^a}¼21.0 GPa with critical temperature (Tc) of {\^a}¼2.8 K. The Tc monotonically increases within the range of our study reaching {\^a}¼9.0 K around 41.0 GPa. These observations coincide with unprecedented chair-to-planar conformational changes of Se6 rings, an abrupt decrease along the c-axis, and negative compression within the ab plane during the phase transition. DFT calculations demonstrate that the flattened Se6 rings within the CuSe layer create a high density of states at the Fermi level. The unique structural features of Cu2I2Se6 imply that superconductivity may emerge in anisotropic Cu-containing materials without square-lattice geometry and magnetic order in the parent compound.",

author = "Weizhao Cai and Wenwen Lin and Li, {Long Hua} and Malliakas, {Christos D.} and Rong Zhang and Matthew Groesbeck and Bao, {Jin Ke} and Dongzhou Zhang and Eran Sterer and Kanatzidis, {Mercouri G.} and Shanti Deemyad",

note = "Funding Information: The authors acknowledge Yansun Yao (University of Saskatchewan) for fruitful discussions on DFT calculations, Haozhe Liu (HPSTAR) for allowing us to use the plate DAC gearbox for helium loading, and Przemys{\l}aw Dera (University of Hawaii at Manoa) for his kind demonstration of the ATREX software. We also acknowledge Z. Valy Vardeny for allowing us to use the superconducting magnet cryostat in his lab. We thank Sergy Tkachev for assistance with helium loading, Jesse Smith for tremendous experimental support, and Jared Coles and Jordan Lybarger for their help with high-pressure powder X-ray data collection. The high pressure single crystal X-ray diffraction data and powder X-ray diffraction data were collected at 13-BM-C of GeoSoilEnviroCARS (The University of Chicago, Sector 13) and at 16-ID-B of HPCAT (Sector 16), Advanced Photon Source (APS), Argonne National Laboratory, respectively. GeoSoilEnviroCARS is supported by the National Science Foundation-Earth Sciences (EAR-1634415) and Department of Energy-GeoSciences (DE-FG02-94ER14466). HPCAT operations are supported by DOE-NNSA{\textquoteright}s Office of Experimental Sciences. Use of the COMPRES-GSECARS gas loading system and PX2 was supported by COMPRES under NSF Cooperative Agreement EAR-1661511 and by GSECARS through NSF Grant EAR-1634415 and DOE Grant DE-FG02-94ER14466. Work at Argonne (sample preparation, characterization, and crystal growth) is supported by the U.S. DOE, Office of Basic Energy Science, Materials Science and Engineering Division. Use of the Advanced Photon Source at Argonne National Laboratory was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. Publisher Copyright: {\textcopyright} 2019 American Chemical Society.",

year = "2019",

month = sep,

day = "25",

doi = "10.1021/jacs.9b06794",

language = "English (US)",

volume = "141",

pages = "15174--15182",

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Cai, W, Lin, W, Li, LH, Malliakas, CD, Zhang, R, Groesbeck, M, Bao, JK, Zhang, D, Sterer, E, Kanatzidis, MG & Deemyad, S 2019, 'Pressure-Induced Superconductivity and Flattened Se₆ Rings in the Wide Band Gap Semiconductor Cu₂I₂Se₆ ', Journal of the American Chemical Society, vol. 141, no. 38, pp. 15174-15182. https://doi.org/10.1021/jacs.9b06794

TY - JOUR

T1 - Pressure-Induced Superconductivity and Flattened Se6 Rings in the Wide Band Gap Semiconductor Cu2I2Se6

AU - Cai, Weizhao

AU - Lin, Wenwen

AU - Li, Long Hua

AU - Malliakas, Christos D.

AU - Zhang, Rong

AU - Groesbeck, Matthew

AU - Bao, Jin Ke

AU - Zhang, Dongzhou

AU - Sterer, Eran

AU - Kanatzidis, Mercouri G.

AU - Deemyad, Shanti

N1 - Funding Information: The authors acknowledge Yansun Yao (University of Saskatchewan) for fruitful discussions on DFT calculations, Haozhe Liu (HPSTAR) for allowing us to use the plate DAC gearbox for helium loading, and Przemysław Dera (University of Hawaii at Manoa) for his kind demonstration of the ATREX software. We also acknowledge Z. Valy Vardeny for allowing us to use the superconducting magnet cryostat in his lab. We thank Sergy Tkachev for assistance with helium loading, Jesse Smith for tremendous experimental support, and Jared Coles and Jordan Lybarger for their help with high-pressure powder X-ray data collection. The high pressure single crystal X-ray diffraction data and powder X-ray diffraction data were collected at 13-BM-C of GeoSoilEnviroCARS (The University of Chicago, Sector 13) and at 16-ID-B of HPCAT (Sector 16), Advanced Photon Source (APS), Argonne National Laboratory, respectively. GeoSoilEnviroCARS is supported by the National Science Foundation-Earth Sciences (EAR-1634415) and Department of Energy-GeoSciences (DE-FG02-94ER14466). HPCAT operations are supported by DOE-NNSA’s Office of Experimental Sciences. Use of the COMPRES-GSECARS gas loading system and PX2 was supported by COMPRES under NSF Cooperative Agreement EAR-1661511 and by GSECARS through NSF Grant EAR-1634415 and DOE Grant DE-FG02-94ER14466. Work at Argonne (sample preparation, characterization, and crystal growth) is supported by the U.S. DOE, Office of Basic Energy Science, Materials Science and Engineering Division. Use of the Advanced Photon Source at Argonne National Laboratory was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. Publisher Copyright: © 2019 American Chemical Society.

PY - 2019/9/25

Y1 - 2019/9/25

N2 - The two major classes of unconventional superconductors, cuprates and Fe-based superconductors, have magnetic parent compounds, are layered, and generally feature square-lattice symmetry. We report the discovery of pressure-induced superconductivity in a nonmagnetic and wide band gap 1.95 eV semiconductor, Cu2I2Se6, with a unique anisotropic structure composed of two types of distinct molecules: Se6 rings and Cu2I2 dimers, which are linked in a three-dimensional framework. Cu2I2Se6 exhibits a concurrent pressure-induced metallization and superconductivity at â¼21.0 GPa with critical temperature (Tc) of â¼2.8 K. The Tc monotonically increases within the range of our study reaching â¼9.0 K around 41.0 GPa. These observations coincide with unprecedented chair-to-planar conformational changes of Se6 rings, an abrupt decrease along the c-axis, and negative compression within the ab plane during the phase transition. DFT calculations demonstrate that the flattened Se6 rings within the CuSe layer create a high density of states at the Fermi level. The unique structural features of Cu2I2Se6 imply that superconductivity may emerge in anisotropic Cu-containing materials without square-lattice geometry and magnetic order in the parent compound.

AB - The two major classes of unconventional superconductors, cuprates and Fe-based superconductors, have magnetic parent compounds, are layered, and generally feature square-lattice symmetry. We report the discovery of pressure-induced superconductivity in a nonmagnetic and wide band gap 1.95 eV semiconductor, Cu2I2Se6, with a unique anisotropic structure composed of two types of distinct molecules: Se6 rings and Cu2I2 dimers, which are linked in a three-dimensional framework. Cu2I2Se6 exhibits a concurrent pressure-induced metallization and superconductivity at â¼21.0 GPa with critical temperature (Tc) of â¼2.8 K. The Tc monotonically increases within the range of our study reaching â¼9.0 K around 41.0 GPa. These observations coincide with unprecedented chair-to-planar conformational changes of Se6 rings, an abrupt decrease along the c-axis, and negative compression within the ab plane during the phase transition. DFT calculations demonstrate that the flattened Se6 rings within the CuSe layer create a high density of states at the Fermi level. The unique structural features of Cu2I2Se6 imply that superconductivity may emerge in anisotropic Cu-containing materials without square-lattice geometry and magnetic order in the parent compound.

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SN - 0002-7863

VL - 141

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JO - Journal of the American Chemical Society

JF - Journal of the American Chemical Society

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ER -

Pressure-Induced Superconductivity and Flattened Se₆ Rings in the Wide Band Gap Semiconductor Cu₂I₂Se₆

Abstract

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CSD 1954498: Experimental Crystal Structure Determination

CSD 1954499: Experimental Crystal Structure Determination

CSD 1954497: Experimental Crystal Structure Determination

Cite this

Pressure-Induced Superconductivity and Flattened Se6 Rings in the Wide Band Gap Semiconductor Cu2I2Se6

Abstract

ASJC Scopus subject areas

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Datasets

CSD 1954498: Experimental Crystal Structure Determination

CSD 1954499: Experimental Crystal Structure Determination

CSD 1954497: Experimental Crystal Structure Determination

Cite this

Pressure-Induced Superconductivity and Flattened Se₆ Rings in the Wide Band Gap Semiconductor Cu₂I₂Se₆