Temperature dependence of the paramagnetic spin excitations in BaFe2As2

Article

关键词: MAGNETIC EXCITATIONS;    IRON;    SUPERCONDUCTIVITY;    SCATTERING;    TRANSITION;    ANISOTROPY;   

DOI  :  10.1103/PhysRevB.86.140403

来源: SCIE

【 摘 要 】

We use inelastic neutron scattering to study temperature dependence of the paramagnetic spin excitations in iron pnictide BaFe2As2 throughout the Brillouin zone. In contrast to a conventional local moment Heisenberg system, where paramagnetic spin excitations are expected to have a Lorentzian function centered at zero energy transfer, the high-energy (h(omega) > 100 meV) paramagnetic spin excitations in BaFe2As2 exhibit spin-wave-like features up to at least 290 K (T = 2.1T(N)). Furthermore, we find that the sizes of the fluctuating magnetic moments (m(2)) approximate to 3.6 mu(2)(B) per Fe are essentially temperature independent from the antiferromagnetic ordered state at 0.05T(N) to 2.1T(N), which differs considerably from the temperature dependent fluctuating moment observed in the iron chalcogenide Fe1.1Te [Zaliznyak et al., Phys. Rev. Lett. 107, 216403 (2011)]. These results suggest unconventional magnetism and strong electron correlation effects in BaFe2As2.

【 授权许可】

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