• Editors' Suggestion

Iron-vacancy superstructure and possible room-temperature antiferromagnetic order in superconducting CsyFe2xSe2

V. Yu. Pomjakushin, D. V. Sheptyakov, E. V. Pomjakushina, A. Krzton-Maziopa, K. Conder, D. Chernyshov, V. Svitlyk, and Z. Shermadini
Phys. Rev. B 83, 144410 – Published 14 April 2011

Abstract

Neutron and x-ray powder and single crystal synchrotron diffraction of CsyFe2xSe2 show the presence of superstructure reflections with propagation vector k=[25,15,1] with respect to the average crystal structure I4/mmm (a~4,c~15 Å). The propagation vector star corresponds to the 5 times bigger unit cell given by transformation A=2a+b, B=a+2b, C=c. A solution for the atomic structure is found in the space group I4/m with an ordered pattern of iron vacancies corresponding to the iron deficiency x=0.29 and Cs stoichiometry y=0.83. The superstructure satellites are more pronounced in the neutron diffraction patterns suggesting that they can have some magnetic contribution. We have sorted out all possible symmetry adapted magnetic configurations and found that the presence of antiferromagnetic ordering with the ordered magnetic moment of Fe with 2μB does not contradict the experimental data. However, the solutions space is highly degenerate and we cannot choose a specific solution. Instead we propose possible magnetic configurations with the Fe magnetic moments in (ab) plane or along c axis. The superstructure is destroyed above Ts500 K by a first-order-like transition.

  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Received 9 February 2011

DOI:https://doi.org/10.1103/PhysRevB.83.144410

©2011 American Physical Society

Authors & Affiliations

V. Yu. Pomjakushin and D. V. Sheptyakov

  • Laboratory for Neutron Scattering, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland

E. V. Pomjakushina, A. Krzton-Maziopa, and K. Conder

  • Laboratory for Developments and Methods, PSI, CH-5232 Villigen PSI, Switzerland

D. Chernyshov and V. Svitlyk

  • Swiss-Norwegian Beam Lines at ESRF, BP220, F-38043 Grenoble, France

Z. Shermadini

  • Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 83, Iss. 14 — 1 April 2011

Reuse & Permissions
Access Options
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review B

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×