Local structure response of phase separation and iron-vacancy order in Kx Fe2-y Se2 superconductor

A. Iadecola, B. Joseph, M. Bendele, G. Aquilanti, H. Takeya, Y. Mizuguchi, Y. Takano, Takashi Mizokawa, N. L. Saini

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

We have studied the local structure of a KxFe2-ySe2 superconductor across the phase separation and iron-vacancy order-disorder temperatures (respectively at ∼520 K and ∼580 K). The combination of Fe K edge and Se K edge extended x-ray absorption fine-structure (EXAFS) measurements reveal the glassy local structure of KxFe2-ySe2, with anomalous behavior of local atomic displacements. We find that the Fe-Se distance remains temperature independent while the Fe-Fe distance suffers a substantial effect of the phase separation. Furthermore, the Fe-Se network shows a reduced disorder in the phase separation regime at lower temperature. The x-ray absorption near-edge structure features follow the local structure anomaly observed by EXAFS and reveal substantially reduced Fe 3d-Se 4p hybridization in the iron-vacancy disordered phase at higher temperature. The results provide further information on the role of nanoscale atomic displacements in the peculiar coexistence of different electronic phases in KxFe2-ySe2 with a filamentary superconducting state embedded in the iron-vacancy ordered magnetic texture.

Original languageEnglish
Article number174509
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume90
Issue number17
DOIs
Publication statusPublished - 2014 Nov 20
Externally publishedYes

Fingerprint

x ray absorption
Phase separation
Superconducting materials
Vacancies
Iron
iron
fine structure
X rays
disorders
Temperature
Order disorder transitions
textures
anomalies
temperature
Textures
electronics

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Electronic, Optical and Magnetic Materials

Cite this

Local structure response of phase separation and iron-vacancy order in Kx Fe2-y Se2 superconductor. / Iadecola, A.; Joseph, B.; Bendele, M.; Aquilanti, G.; Takeya, H.; Mizuguchi, Y.; Takano, Y.; Mizokawa, Takashi; Saini, N. L.

In: Physical Review B - Condensed Matter and Materials Physics, Vol. 90, No. 17, 174509, 20.11.2014.

Research output: Contribution to journalArticle

Iadecola, A. ; Joseph, B. ; Bendele, M. ; Aquilanti, G. ; Takeya, H. ; Mizuguchi, Y. ; Takano, Y. ; Mizokawa, Takashi ; Saini, N. L. / Local structure response of phase separation and iron-vacancy order in Kx Fe2-y Se2 superconductor. In: Physical Review B - Condensed Matter and Materials Physics. 2014 ; Vol. 90, No. 17.
@article{765fb7b03ac64956aa8773b29f08fa14,
title = "Local structure response of phase separation and iron-vacancy order in Kx Fe2-y Se2 superconductor",
abstract = "We have studied the local structure of a KxFe2-ySe2 superconductor across the phase separation and iron-vacancy order-disorder temperatures (respectively at ∼520 K and ∼580 K). The combination of Fe K edge and Se K edge extended x-ray absorption fine-structure (EXAFS) measurements reveal the glassy local structure of KxFe2-ySe2, with anomalous behavior of local atomic displacements. We find that the Fe-Se distance remains temperature independent while the Fe-Fe distance suffers a substantial effect of the phase separation. Furthermore, the Fe-Se network shows a reduced disorder in the phase separation regime at lower temperature. The x-ray absorption near-edge structure features follow the local structure anomaly observed by EXAFS and reveal substantially reduced Fe 3d-Se 4p hybridization in the iron-vacancy disordered phase at higher temperature. The results provide further information on the role of nanoscale atomic displacements in the peculiar coexistence of different electronic phases in KxFe2-ySe2 with a filamentary superconducting state embedded in the iron-vacancy ordered magnetic texture.",
author = "A. Iadecola and B. Joseph and M. Bendele and G. Aquilanti and H. Takeya and Y. Mizuguchi and Y. Takano and Takashi Mizokawa and Saini, {N. L.}",
year = "2014",
month = "11",
day = "20",
doi = "10.1103/PhysRevB.90.174509",
language = "English",
volume = "90",
journal = "Physical Review B-Condensed Matter",
issn = "0163-1829",
publisher = "American Institute of Physics Publising LLC",
number = "17",

}

TY - JOUR

T1 - Local structure response of phase separation and iron-vacancy order in Kx Fe2-y Se2 superconductor

AU - Iadecola, A.

AU - Joseph, B.

AU - Bendele, M.

AU - Aquilanti, G.

AU - Takeya, H.

AU - Mizuguchi, Y.

AU - Takano, Y.

AU - Mizokawa, Takashi

AU - Saini, N. L.

PY - 2014/11/20

Y1 - 2014/11/20

N2 - We have studied the local structure of a KxFe2-ySe2 superconductor across the phase separation and iron-vacancy order-disorder temperatures (respectively at ∼520 K and ∼580 K). The combination of Fe K edge and Se K edge extended x-ray absorption fine-structure (EXAFS) measurements reveal the glassy local structure of KxFe2-ySe2, with anomalous behavior of local atomic displacements. We find that the Fe-Se distance remains temperature independent while the Fe-Fe distance suffers a substantial effect of the phase separation. Furthermore, the Fe-Se network shows a reduced disorder in the phase separation regime at lower temperature. The x-ray absorption near-edge structure features follow the local structure anomaly observed by EXAFS and reveal substantially reduced Fe 3d-Se 4p hybridization in the iron-vacancy disordered phase at higher temperature. The results provide further information on the role of nanoscale atomic displacements in the peculiar coexistence of different electronic phases in KxFe2-ySe2 with a filamentary superconducting state embedded in the iron-vacancy ordered magnetic texture.

AB - We have studied the local structure of a KxFe2-ySe2 superconductor across the phase separation and iron-vacancy order-disorder temperatures (respectively at ∼520 K and ∼580 K). The combination of Fe K edge and Se K edge extended x-ray absorption fine-structure (EXAFS) measurements reveal the glassy local structure of KxFe2-ySe2, with anomalous behavior of local atomic displacements. We find that the Fe-Se distance remains temperature independent while the Fe-Fe distance suffers a substantial effect of the phase separation. Furthermore, the Fe-Se network shows a reduced disorder in the phase separation regime at lower temperature. The x-ray absorption near-edge structure features follow the local structure anomaly observed by EXAFS and reveal substantially reduced Fe 3d-Se 4p hybridization in the iron-vacancy disordered phase at higher temperature. The results provide further information on the role of nanoscale atomic displacements in the peculiar coexistence of different electronic phases in KxFe2-ySe2 with a filamentary superconducting state embedded in the iron-vacancy ordered magnetic texture.

UR - http://www.scopus.com/inward/record.url?scp=84915818543&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84915818543&partnerID=8YFLogxK

U2 - 10.1103/PhysRevB.90.174509

DO - 10.1103/PhysRevB.90.174509

M3 - Article

AN - SCOPUS:84915818543

VL - 90

JO - Physical Review B-Condensed Matter

JF - Physical Review B-Condensed Matter

SN - 0163-1829

IS - 17

M1 - 174509

ER -