Magnetically polarized Ir dopant atoms in superconducting Ba(Fe_1-xIr_x)₂As₂

Journal Article · Wed Apr 25 04:00:00 EDT 2012 · Phys. Rev. B

DOI:https://doi.org/10.1103/PhysRevB.85.140514· OSTI ID:1081149

Dean, M. P.M. ^[1]; Kim, M. G. ^[2]; Kreyssig, A. ^[2]; Kim, J. W. ^[3]; Liu, X. ^[1]; Ryan, P. J. ^[3]; Thaler, A. ^[2]; Budko, S. L. ^[2]; Strassheim, W. ^[2]; Canfield, P. C. ^[2]; Hill, J. P. ^[1]; Goldman, A. I. ^[2]

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1. Brookhaven National Lab. (BNL), Upton, NY (United States)
2. Iowa State Univ., Ames, IA (United States)
3. Argonne National Lab. (ANL), Argonne, IL (United States)

We investigate the magnetic polarization of the Ir 5d dopant states in the pnictide superconductor Ba(Fe_1-xIr_x)₂As₂ with x=0.027(2) using Ir L₃ 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, ξ_mag>2800 and >850 Å, in the abplane and along the c 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 T_N=74(2) K. At 5 K we find that magnetic order coexists microscopically with superconductivity in Ba(Fe_1-xIr_x)₂As₂. The energy dependence of the XRMS through the Ir L₃ edge shows a non-Lorentzian line shape, which we explain in terms of interference between Ir resonant scattering and Fe nonresonant magnetic scattering.

• Research Organization: Energy Frontier Research Centers (EFRC); Center for Emergent Superconductivity (CES)
• Sponsoring Organization: USDOE SC Office of Basic Energy Sciences (SC-22)
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 1081149
• Journal Information: Phys. Rev. B, Journal Name: Phys. Rev. B Vol. 85
• Publisher: American Physical Society (APS)
• Country of Publication: United States
• Language: English

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