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

Journal Article · · Proceedings of the National Academy of Sciences of the United States of America
 [1];  [2];  [3];  [4];  [5];  [6];  [7];  [7];  [7];  [8];  [8]; ORCiD logo [8];  [9];  [2]
  1. National Tsing Hua Univ. (Taiwan)
  2. Tamkang Univ. (Taiwan)
  3. Academia Sinica, Taipei (Taiwan); National Univ. of Science and Technology, Taipei (Taiwan)
  4. Tamkang Univ. (Taiwan); National Synchrotron Radiation Research Center (Taiwan)
  5. Tamkang Univ. (Taiwan); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  6. National Univ. of Kaohsiung (Taiwan)
  7. National Synchrotron Radiation Research Center (Taiwan)
  8. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  9. National Tsing Hua Univ. (Taiwan); Academia Sinica, Taipei (Taiwan)
+ Show Author Affiliations

We investigate the evolution of superconductivity in K2–xFe4+ySe5 using temperature-dependent X-ray absorption and resonant inelastic X-ray scattering techniques. Magnetization measurements show that polycrystalline superconducting (SC) K1.9Fe4.2Se5 has 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 3d and 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+ySe5 superconductors, providing deeper insight into the electron pairing mechanisms of superconductivity.

Research Organization:
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
Sponsoring Organization:
USDOE Office of Science (SC)
Grant/Contract Number:
AC02-05CH11231
OSTI ID:
1581386
Journal Information:
Proceedings of the National Academy of Sciences of the United States of America, Vol. 116, Issue 45; ISSN 0027-8424
Publisher:
National Academy of SciencesCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 3 works
Citation information provided by
Web of Science

References (46)

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
Superconductivity in the PbO-type structure  -FeSe journal September 2008
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
Electronic and atomic structures of the Sr3Ir4Sn13 single crystal: A possible charge density wave material journal January 2017
Iron-Based Layered Superconductor La[O 1- x F x ]FeAs ( x = 0.05−0.12) with T c = 26 K journal March 2008
Orbital-Selective Mott Phase in Multiorbital Models for Alkaline Iron Selenides K 1 − x Fe 2 − y Se 2 journal April 2013
Direct observation of nanoscale interface phase in the superconducting chalcogenide K x Fe 2 − y Se 2 with intrinsic phase separation journal January 2015
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 ≤ x ≤ 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 ≤ x ≤ 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
Strong Correlations and Magnetic Frustration in the High Tc Iron Pnictides text January 2008
Evidence for weak electronic correlations in Fe-pnictides text January 2009
Anion height dependence of Tc for the Fe-based superconductor text January 2010
Phase transition, superstructure and physical properties of K2Fe4Se5 text January 2011
Antiferromagnetic order and spin dynamics in iron-based superconductors text January 2015
High Temperature Superconductivity in Iron Pnictides and Chalcogenides text January 2016

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