Room-Temperature Ba(Fe1-x Cox)2 As2 is not Tetragonal: Direct Observation of Magnetoelastic Interactions in Pnictide Superconductors

Claudia Cantoni; Michael A McGuire; Bayrammurad Saparov; Andrew F May; Trevor Keiber; Frank Bridges; Athena S Sefat; Brian C Sales

doi:10.1002/adma.201404079

Room-Temperature Ba(Fe1-x Cox)2 As2 is not Tetragonal: Direct Observation of Magnetoelastic Interactions in Pnictide Superconductors

Adv Mater. 2015 May 6;27(17):2715-21. doi: 10.1002/adma.201404079. Epub 2015 Mar 23.

Authors

Claudia Cantoni¹, Michael A McGuire, Bayrammurad Saparov, Andrew F May, Trevor Keiber, Frank Bridges, Athena S Sefat, Brian C Sales

Affiliation

¹ Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.

PMID: 25809406
DOI: 10.1002/adma.201404079

Abstract

Lattice distortions corresponding to Ba displacements with respect to the FeAs sublattice are revealed to break the room-temperature tetragonal symmetry in Ba(Fe1-x Cox)2 As2. The displacements yield twin domains of the size of ≈10 nm. The domain size correlates with the magnitude of the local Fe magnetic moment and its non-monotonic dependence on Co concentration.

Keywords: iron-based superconductors; lattice distortions; local magnetic moment; scanning transmission electron microscopy.