Spin excitations in BaFe1.84Co0.16As2 superconductor observed by inelastic neutron scattering

D. Parshall; K. A. Lokshin; Jennifer Niedziela; A. D. Christianson; M. D. Lumsden; H. A. Mook; S. E. Nagler; M. A. McGuire; M. B. Stone; D. L. Abernathy; A. S. Sefat; B. C. Sales; D. G. Mandrus; T. Egami

doi:10.1103/PhysRevB.80.012502

Spin excitations in BaFe1.84Co0.16As2 superconductor observed by inelastic neutron scattering

D. Parshall, K. A. Lokshin, Jennifer Niedziela, A. D. Christianson, M. D. Lumsden, H. A. Mook, S. E. Nagler, M. A. McGuire, M. B. Stone, D. L. Abernathy, A. S. Sefat, B. C. Sales, D. G. Mandrus, T. Egami

DOI 10.1103/PhysRevB.80.012502 · Physical Review B

T1

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Abstract

Superconductivity appears to compete against the spin-density wave in Fe pnictides. However, optimally cobalt-doped samples show a quasi-two-dimensional spin excitation centered at the (0.5, 0.5, L) wave vector, “the spin-resonance peak,” which is strongly tied to the onset of superconductivity. By inelastic neutron scattering on single crystals we show the similarities and differences of the spin excitations in BaFe1.84Co0.16As2 with respect to the spin excitations in the high-temperature superconducting cuprates. As in the cuprates, the resonance occurs as an enhancement to a part of the spin-excitation spectrum, which extends to higher-energy transfer and higher temperature. However, unlike in the cuprates, the resonance peak in this compound is asymmetric in energy.

Source-reported materials — not catalogue approval

Formula	Reported Tc (K)	Pressure (GPa)	Type
BaFe1.84Co0.16As2 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	22	Pressure not reported	onset