Evolution of superconductivity in K2–xFe4+ySe5: Spectroscopic studies of X-ray absorption and emission

doi:10.1073/pnas.1912610116

This content will become publicly available on November 5, 2020

Title: Evolution of superconductivity in K _2–xFe _4+ySe ₅: Spectroscopic studies of X-ray absorption and emission

Abstract

We investigate the evolution of superconductivity in K _2–xFe _4+ySe ₅using temperature-dependent X-ray absorption and resonant inelastic X-ray scattering techniques. Magnetization measurements show that polycrystalline superconducting (SC) K _1.9Fe _4.2Se ₅has a critical temperature ( T _c) of ~31 K with a varying superconducting volume fraction, which significantly depends on its synthesis temperature. An increase in Fe-structural/vacancy disorder in SC samples with more Fe atoms occupying vacant 4d sites is found to be closely related to the decrease in the spin magnetic moment of Fe. Moreover, the nearest-neighbor Fe–Se bond length in SC samples exceeds that in the non-SC (NS) sample, K ₂Fe ₄Se ₅, which indicates a weaker hybridization between the Fe 3 dand Se 4 pstates in SC samples. These results clearly demonstrate the correlations among the local electronic and atomic structures and the magnetic properties of K _2–xFe _4+ySe ₅superconductors, providing deeper insight into the electron pairing mechanisms of superconductivity.

Authors:

Wang, H. T. ^[1]; Ghosh, Anirudha ^[2]; Wang, C. H. ^[3]; Hsieh, S. H. ^[4]; Shao, Y. C. ^[5]; Chiou, J. W. ^[6]; Chen, C. L. ^[7]; Pao, C. W. ^[7]; Lee, J. F. ^[7]; Liu, Y. S. ^[8]; Chuang, Y. D. ^[8];

^[8]; Wu, M. K. ^[9]; Pong, W. F. ^[2]

National Tsing Hua Univ. (Taiwan)
Tamkang Univ. (Taiwan)
Academia Sinica, Taipei (Taiwan); National Univ. of Science and Technology, Taipei (Taiwan)
Tamkang Univ. (Taiwan); National Synchrotron Radiation Research Center (Taiwan)
Tamkang Univ. (Taiwan); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
National Univ. of Kaohsiung (Taiwan)
National Synchrotron Radiation Research Center (Taiwan)
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
National Tsing Hua Univ. (Taiwan); Academia Sinica, Taipei (Taiwan)

Publication Date:: 2019-11-05

Research Org.:: Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

Sponsoring Org.:: USDOE Office of Science (SC)

OSTI Identifier:: 1581386

Grant/Contract Number:: AC02-05CH11231

Resource Type:: Accepted Manuscript

Journal Name:: Proceedings of the National Academy of Sciences of the United States of America

Additional Journal Information:: Journal Volume: 116; Journal Issue: 45; Journal ID: ISSN 0027-8424

Publisher:: National Academy of Sciences

Country of Publication:: United States

Language:: English

Subject:: 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; superconductivity; Fe vacancy disorder; X-ray absorption spectroscopy; resonant inelastic X-ray scattering

Citation Formats


                    Wang, H. T., Ghosh, Anirudha, Wang, C. H., Hsieh, S. H., Shao, Y. C., Chiou, J. W., Chen, C. L., Pao, C. W., Lee, J. F., Liu, Y. S., Chuang, Y. D., Guo, J. H., Wu, M. K., and Pong, W. F. Evolution of superconductivity in K2–xFe4+ySe5: Spectroscopic studies of X-ray absorption and emission.  United States: N. p., 2019. 
        Web.  doi:10.1073/pnas.1912610116.

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                    Wang, H. T., Ghosh, Anirudha, Wang, C. H., Hsieh, S. H., Shao, Y. C., Chiou, J. W., Chen, C. L., Pao, C. W., Lee, J. F., Liu, Y. S., Chuang, Y. D., Guo, J. H., Wu, M. K., & Pong, W. F. Evolution of superconductivity in K2–xFe4+ySe5: Spectroscopic studies of X-ray absorption and emission.  United States.  doi:10.1073/pnas.1912610116.

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                    Wang, H. T., Ghosh, Anirudha, Wang, C. H., Hsieh, S. H., Shao, Y. C., Chiou, J. W., Chen, C. L., Pao, C. W., Lee, J. F., Liu, Y. S., Chuang, Y. D., Guo, J. H., Wu, M. K., and Pong, W. F. Tue .  
        "Evolution of superconductivity in K2–xFe4+ySe5: Spectroscopic studies of X-ray absorption and emission".  United States.  doi:10.1073/pnas.1912610116.

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@article{osti_1581386,

  title        = {Evolution of superconductivity in K2–xFe4+ySe5: Spectroscopic studies of X-ray absorption and emission},

  author       = {Wang, H. T. and Ghosh, Anirudha and Wang, C. H. and Hsieh, S. H. and Shao, Y. C. and Chiou, J. W. and Chen, C. L. and Pao, C. W. and Lee, J. F. and Liu, Y. S. and Chuang, Y. D. and Guo, J. H. and Wu, M. K. and Pong, W. F.},

  abstractNote = {We investigate the evolution of superconductivity in K2–xFe4+ySe5using temperature-dependent X-ray absorption and resonant inelastic X-ray scattering techniques. Magnetization measurements show that polycrystalline superconducting (SC) K1.9Fe4.2Se5has a critical temperature (Tc) of ~31 K with a varying superconducting volume fraction, which significantly depends on its synthesis temperature. An increase in Fe-structural/vacancy disorder in SC samples with more Fe atoms occupying vacant 4d sites is found to be closely related to the decrease in the spin magnetic moment of Fe. Moreover, the nearest-neighbor Fe–Se bond length in SC samples exceeds that in the non-SC (NS) sample, K2Fe4Se5, which indicates a weaker hybridization between the Fe 3dand Se 4pstates in SC samples. These results clearly demonstrate the correlations among the local electronic and atomic structures and the magnetic properties of K2–xFe4+ySe5superconductors, providing deeper insight into the electron pairing mechanisms of superconductivity.},

  doi          = {10.1073/pnas.1912610116},

  journal      = {Proceedings of the National Academy of Sciences of the United States of America},

  number       = 45,

  volume       = 116,

  place        = {United States},

  year         = {2019},

  month        = {11}

}

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This content will become publicly available on November 5, 2020

Title: Evolution of superconductivity in K 2–xFe 4+ySe 5: Spectroscopic studies of X-ray absorption and emission

Abstract

Citation Formats

Antiferromagnetic order and spin dynamics in iron-based superconductors journal, August 2015

Phase transition, superstructure and physical properties of K 2 Fe 4 Se 5 journal, July 2011

Resonant inelastic x-ray scattering at the Fe L 3 edge of the one-dimensional chalcogenide BaFe 2 Se 3 journal, October 2013

Electronic and magnetic phase diagram in KxFe2-ySe2 superconductors journal, January 2012

Observation of universal strong orbital-dependent correlation effects in iron chalcogenides journal, July 2015

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Strong Correlations and Magnetic Frustration in the High T c Iron Pnictides journal, August 2008

Superconducting properties of single-crystalline A x Fe 2 − y Se 2 ( A = Rb, K) studied using muon spin spectroscopy journal, March 2012

Phase relations in K x Fe 2 − y Se 2 and the structure of superconducting K x Fe 2 Se 2 via high-resolution synchrotron diffraction journal, November 2012

Electronic structure and phase separation of superconducting and nonsuperconducting K x Fe 2 − y Se 2 revealed by x-ray photoemission spectroscopy journal, December 2013

Common Crystalline and Magnetic Structure of Superconducting A 2 Fe 4 Se 5 ( A = K , Rb , Cs , Tl ) Single Crystals Measured Using Neutron Diffraction journal, September 2011

Resonant inelastic x-ray scattering studies of elementary excitations journal, June 2011

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Direct observation of nanoscale interface phase in the superconducting chalcogenide K x Fe 2 − y Se 2 with intrinsic phase separation journal, January 2015

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Modular soft x-ray spectrometer for applications in energy sciences and quantum materials journal, January 2017

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Superconductivity in the iron selenide K x Fe 2 Se 2 ( 0 ≤ x ≤ 1.0 ) journal, November 2010

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Suppression of the antiferromagnetic order when approaching the superconducting state in a phase-separated crystal of K x Fe 2 − y Se 2 journal, September 2017

Electronic structure of Co-substituted FeSe superconductor probed by soft x-ray spectroscopy and density functional theory journal, July 2014

Anion height dependence of T c for the Fe-based superconductor journal, April 2010

Evidence for weak electronic correlations in iron pnictides journal, July 2009

Theoretical x-ray absorption fine structure standards journal, July 1991

High-temperature superconductivity in iron pnictides and chalcogenides journal, March 2016

Local structure response of phase separation and iron-vacancy order in K x Fe 2 − y Se 2 superconductor journal, November 2014

The development of the superconducting PbO-type β-FeSe and related compounds journal, May 2009

Core-level spectroscopic study of FeO and Fe S 2 journal, February 2005

Electronic structure of vacancy-ordered iron-selenide K 0.5 Fe 1.75 Se 2 journal, April 2013

An overview of the Fe-chalcogenide superconductors journal, July 2015

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Title: Evolution of superconductivity in K _2–xFe _4+ySe ₅: Spectroscopic studies of X-ray absorption and emission

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Phase relations in K $_{x}$ Fe $_{2 - y}$ Se $_{2}$ and the structure of superconducting K $_{x}$ Fe $_{2}$ Se $_{2}$ via high-resolution synchrotron diffraction
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Electronic structure and phase separation of superconducting and nonsuperconducting K x Fe 2 − y Se 2 revealed by x-ray photoemission spectroscopy
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Resonant inelastic x-ray scattering studies of elementary excitations
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Role of the extra Fe in K 2− x Fe 4+ y Se 5 superconductors
journal, January 2019

Disordered Fe vacancies and superconductivity in potassium-intercalated iron selenide (K _{2− x} Fe _{4+ y} Se ₅ )
journal, July 2015

X-Ray spectra and electronic correlations of FeSe1–xTex
journal, January 2011

Anisotropy in the thermal hysteresis of resistivity and charge density wave nature of single crystal SrFeO3-δ: X-ray absorption and photoemission studies
journal, March 2017

Modular soft x-ray spectrometer for applications in energy sciences and quantum materials
journal, January 2017

Resonant inelastic x-ray scattering study of entangled spin-orbital excitations in superconducting PrFeAsO 0.7
journal, July 2016

Superconductivity in the iron selenide $K_{x} {Fe}_{2} {Se}_{2}$ $(0 \leq x \leq 1.0)$
journal, November 2010

Multiple-scattering x-ray-absorption fine-structure analysis and thermal expansion of alkali halides
journal, November 1993

Suppression of the antiferromagnetic order when approaching the superconducting state in a phase-separated crystal of K x Fe 2 − y Se 2
journal, September 2017

Electronic structure of Co-substituted FeSe superconductor probed by soft x-ray spectroscopy and density functional theory
journal, July 2014

Anion height dependence of T _c for the Fe-based superconductor
journal, April 2010

Evidence for weak electronic correlations in iron pnictides
journal, July 2009

Theoretical x-ray absorption fine structure standards
journal, July 1991

High-temperature superconductivity in iron pnictides and chalcogenides
journal, March 2016

Local structure response of phase separation and iron-vacancy order in K x Fe 2 − y Se 2 superconductor
journal, November 2014

The development of the superconducting PbO-type β-FeSe and related compounds
journal, May 2009

Core-level spectroscopic study of FeO and Fe S 2
journal, February 2005

Electronic structure of vacancy-ordered iron-selenide K 0.5 Fe 1.75 Se 2
journal, April 2013

An overview of the Fe-chalcogenide superconductors
journal, July 2015

Archimedean solidlike superconducting framework in phase-separated $K_{0.8} F e_{1.6 + x} S e_{2} (0 \leq x \leq 0.15)$
journal, February 2015

Superconductivity close to magnetic instability in $Fe {({Se}_{1 - x} {Te}_{x})}_{0.82}$
journal, December 2008

Evidence for Majorana bound states in an iron-based superconductor
journal, August 2018

Colloquium : The unexpected properties of alkali metal iron selenide superconductors
journal, May 2013

Anisotropy in the magnetic interaction and lattice-orbital coupling of single crystal Ni3TeO6
journal, October 2018