Competition between stripe and checkerboard magnetic instabilities in Mn-doped BaFe2As2

Journal Article · Sun Jan 01 04:00:00 EST 2012 · Physical Review B

OSTI ID:1050325

Pratt, Daniel ^[1]; Kim, M. G. ^[1]; Ran, S. ^[1]; Thaler, A. ^[1]; Granroth, Garrett E ^[2]; Marty, Karol J ^[2]; Tian, W. ^[3]; Zarestky, J. L. ^[1]; Lumsden, Mark D ^[2]; Budko, S L ^[1]; Canfield, P. C. ^[4]; Goldman, A. I. ^[1]; Mcqueeney, R J ^[1]; Tucker, G. S. ^[1]

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1. Ames Laboratory and Iowa State University
2. ORNL
3. University of Tennessee, Knoxville (UTK)
4. Ames Laboratory

The appearance of unconventional superconductivity often requires the suppression of an antiferromagnetic (AFM) ordered state by tuning the chemical composition. In BaFe2As2, the AFM ordered state is driven by Fermi surface nesting, resulting in stripe magnetic ordering with propagation vector Qstripe = (; 0) (in Fe square lattice notation). Co substitution acts as an electron donor that destabilizes the nesting condition,1 leading to suppression of the stripe AFM ordering2 and the appearance of superconductivity.3,4 Mn is nominally the hole-doping counterpart of Co which should also detune the Fermi surface nesting, but it is not a superconductor.5 Here we report that Mn doping does not act solely as a hole donor, but instead introduces strong spin uctuations at a wavevector (; ) that is unrelated to the Fermi surface topology of BaFe2As2. Spin uctuations at (; ) and (; 0) coexist, suggesting the Mn dopants act as local magnetic impurities that polarize neighbouring Fe/Mn spins, potentially disrupting superconductivity.

• Research Organization: Oak Ridge National Laboratory (ORNL); High Flux Isotope Reactor; Spallation Neutron Source
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1050325
• Journal Information: Physical Review B, Journal Name: Physical Review B Journal Issue: 2 Vol. 86; ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BINDING ENERGY
CHEMICAL COMPOSITION
ELECTRONS
FERMI LEVEL
IMPURITIES
SPIN
SUPERCONDUCTIVITY
TOPOLOGY
TUNING
VALENCE
VECTORS