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Neutron-Scattering Measurements of Spin Excitations in LaFeAsO and Ba(Fe0.953Co0.047)2As2: Evidence for a Sharp Enhancement of Spin Fluctuations by Nematic Order
Physical Review Letters
  • Qiang Zhang, Iowa State University
  • Rafael M. Fernandes, University of Minnesota
  • Jagat Lamsal, Iowa State University
  • Jiaqiang Yan, Oak Ridge National Laboratory
  • Songxue Chi, Oak Ridge National Laboratory
  • Gregory S. Tucker, Iowa State University
  • Daniel K. Pratt, National Institute of Standards and Technology
  • Jeffrey W. Lynn, National Institute of Standards and Technology
  • R. William McCallum, Iowa State University
  • Paul C. Canfield, Iowa State University
  • Thomas A. Lograsso, Iowa State University
  • Alan I. Goldman, Iowa State University
  • David Vaknin, Iowa State University
  • Robert J. McQueeney, Iowa State University
Document Type
Article
Publication Version
Published Version
Publication Date
2-6-2015
DOI
10.1103/PhysRevLett.114.057001
Abstract
Inelastic neutron scattering is employed to investigate the impact of electronic nematic order on the magnetic spectra of LaFeAsO and Ba(Fe0.953Co0.047)2As2. These materials are ideal to study the paramagnetic-nematic state, since the nematic order, signaled by the tetragonal-to-orthorhombic transition at TS, sets in well above the stripe antiferromagnetic ordering at TN. We find that the temperature-dependent dynamic susceptibility displays an anomaly at TS followed by a sharp enhancement in the spin-spin correlation length, revealing a strong feedback effect of nematic order on the low-energy magnetic spectrum. Our findings can be consistently described by a model that attributes the structural or nematic transition to magnetic fluctuations, and unveils the key role played by nematic order in promoting the long-range stripe antiferromagnetic order in iron pnictides.
Comments

This article is from Physical Review Letters 114 (2015): 057001, doi:10.1103/PhysRevLett.114.057001.

Rights
Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.
Language
en
Citation Information
Qiang Zhang, Rafael M. Fernandes, Jagat Lamsal, Jiaqiang Yan, et al.. "Neutron-Scattering Measurements of Spin Excitations in LaFeAsO and Ba(Fe0.953Co0.047)2As2: Evidence for a Sharp Enhancement of Spin Fluctuations by Nematic Order" Physical Review Letters Vol. 114 Iss. 5 (2015) p. 057001
Available at: http://works.bepress.com/thomas_lograsso/232/