%0 Journal Article
%A Waßer, F.
%A Schneidewind, A.
%A Sidis, Y.
%A Wurmehl, S.
%A Aswartham, S.
%A Büchner, B.
%A Braden, M.
%T Spin reorientation in Ba $_{0.65}$ Na $_{0.35}$ Fe $_{2}$ As $_{2}$ studied by single-crystal neutron diffraction
%J Physical review / B
%V 91
%N 6
%@ 1098-0121
%C College Park, Md.
%I APS
%M FZJ-2015-03054
%P 060505
%D 2015
%X We have studied the magnetic ordering in Ba1−xNaxFe2As2 with 0.25≤x≤0.4 by unpolarized and polarized neutron diffraction using single crystals. Unlike most FeAs-based compounds that magnetically order, Na-doped BaFe2As2 exhibits two successive magnetic transitions: For x=0.35, upon cooling, magnetic order occurs at ∼70 K with in-plane magnetic moments being arranged as in pure or Ni-, Co-, or K-doped BaFe2As2 samples. At a temperature of ∼46 K a second phase transition occurs, which the single-crystal neutron-diffraction experiments can unambiguously identify as a spin reorientation. At low temperatures, the ordered magnetic moments in Ba0.65Na0.35Fe2As2 point along the c direction. The two nearly degenerate magnetic states document orbital degeneracy to persist in the superconducting phase.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000350251500001
%R 10.1103/PhysRevB.91.060505
%U https://juser.fz-juelich.de/record/190096