Neutron Scattering Measurements of Anisotropic Magnetic Exchange Interactions in Semiconducting K0.85Fe1.54Se2 (TN=280K)

Journal Article · Wed Jan 01 00:00:00 EST 2014 · Physical Review Letters

OSTI ID:1134173

Abernathy, Douglas L ^[1]; Birgeneau, R. J. ^[2]; Gao, Miao ^[3]; Lu, Zhong-Yi ^[3]; Zhao, Jun ^[4]; Zhao, Y. ^[5]

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1. ORNL
2. University of California, Berkeley
3. Renmin University of China
4. Fudan University, China
5. NIST and Univ. of MD

We use neutron scattering to study the spin excitations associated with the stripe antiferromagnetic (AFM) order in semiconducting K0.85Fe1.54Se2 (TN=280 K). We show that the spin wave spectra can be accurately described by an effective Heisenberg Hamiltonian with highly anisotropic in-plane couplings at T= 5 K. At high temperature (T= 300 K) above TN, short range magnetic correlation with anisotropic correlation lengths are observed. Our results suggest that, despite the dramatic difference in the Fermi surface topology, the in-plane anisotropic magnetic coupings are a fundamental property of the iron based compounds; this implies that their antiferromagnetism may originate from local strong correlation effects rather than weak coupling Fermi surface nesting.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1134173
• Journal Information: Physical Review Letters, Vol. 112
• Country of Publication: United States
• Language: English