Abstract
We investigate the magnetic polarization of the Ir dopant states in the pnictide superconductor Ba(FeIr)As with using Ir edge x-ray resonant magnetic scattering (XRMS). Despite the fact that doping partially suppresses the antiferromagnetic transition, we find that magnetic order survives around the Ir dopant sites. The Ir states are magnetically polarized with commensurate stripe-like antiferromagnetic order and long correlations lengths, and 850 Å, in the plane and along the axis, respectively, driven by their interaction with the Fe spins. This Ir magnetic order persists up to the Néel transition of the majority Fe spins at K. At 5 K we find that magnetic order coexists microscopically with superconductivity in Ba(FeIr)As. The energy dependence of the XRMS through the Ir edge shows a non-Lorentzian line shape, which we explain in terms of interference between Ir resonant scattering and Fe nonresonant magnetic scattering.
- Received 20 February 2012
DOI:https://doi.org/10.1103/PhysRevB.85.140514
©2012 American Physical Society