title: Incommensurate spin-density wave order in electron-doped BaFe2 As2 superconductors.
abstract: Neutron diffraction studies of Ba(Fe(1-x)Co(x))(2)As)(2) reveal that commensurate antiferromagnetic order gives way to incommensurate magnetic order for Co compositions between 0.056 < x < 0.06. The incommensurability has the form of a small transverse splitting (0, ± ε, 0) from the commensurate antiferromagnetic propagation vector Q(AFM) = (1,0,1) (in orthorhombic notation) where ε ≈ 0.02-0.03 and is composition dependent. The results are consistent with the formation of a spin-density wave driven by Fermi surface nesting of electron and hole pockets and confirm the itinerant nature of magnetism in the iron arsenide superconductors.
authors.affiliation: Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA.
authors.forename: D K
authors.initials: DK
authors.lastname: Pratt
authors.forename: M G
authors.initials: MG
authors.lastname: Kim
authors.forename: A
authors.initials: A
authors.lastname: Kreyssig
authors.forename: Y B
authors.initials: YB
authors.lastname: Lee
authors.forename: G S
authors.initials: GS
authors.lastname: Tucker
authors.forename: A
authors.initials: A
authors.lastname: Thaler
authors.forename: W
authors.initials: W
authors.lastname: Tian
authors.forename: J L
authors.initials: JL
authors.lastname: Zarestky
authors.forename: S L
authors.initials: SL
authors.lastname: Bud'ko
authors.forename: P C
authors.initials: PC
authors.lastname: Canfield
authors.forename: B N
authors.initials: BN
authors.lastname: Harmon
authors.forename: A I
authors.initials: AI
authors.lastname: Goldman
authors.forename: R J
authors.initials: RJ
authors.lastname: McQueeney