C-axis Phonons in Fe-As Based Superconductors Investigated by Inelastic X-ray Scattering

D. Reznik; K. Lokshin; D. C. Mitchell; D. Parshall; W. Dmowski; D. Lamago; R. Heid; K. -P. Bohnen; A. S. Sefat; M. A. McGuire; B. C. Sales; D. G. Mandrus; A. Asubedi; D. J. Singh; A. Alatas; M. H. Upton; A. H. Said; Yu. Shvyd'ko; T. Egami

arXiv · 0810.4941

C-axis Phonons in Fe-As Based Superconductors Investigated by Inelastic X-ray Scattering

D. Reznik·K. Lokshin·D. C. Mitchell·D. Parshall·W. Dmowski·D. Lamago·R. Heid·K. -P. Bohnen·A. S. Sefat·M. A. McGuire·B. C. Sales·D. G. Mandrus·A. Asubedi·D. J. Singh·A. Alatas·M. H. Upton·A. H. Said·Yu. Shvyd'ko·T. Egami

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Abstract

In Fe-As based superconductors magnetism and superconductivity show strong sensitivity to the lattice, suggesting a possibility of unconventional electron-phonon coupling. We investigated c-axis polarized phonons in doped and undoped BaFe2As2 by inelastic X-ray scattering. Phonon peak positions and linewidths did not vary significantly as a function of doping either by Co or by K. The linewidth of the Fe vibration shows unusual wavevector-dependence, which may be due to hybridization with in-plane modes. Comparison with the density functional theory shows significant difference for the energy of the As-As vibrations (Raman active at the zone center) but not for the Fe-As vibrations (infrared-active at the zone center). This behavior cannot be explained by a 10% softening of Fe-As interaction strength as proposed previously for in-plane polarized vibrations.

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D. Reznik, K. Lokshin, D. C. Mitchell, D. Parshall, W. Dmowski, D. Lamago, R. Heid, K. -P. Bohnen, A. S. Sefat, M. A. McGuire, B. C. Sales, D. G. Mandrus, A. Asubedi, D. J. Singh, A. Alatas, M. H. Upton, A. H. Said, Yu. Shvyd'ko, T. Egami. 2008-10-27. C-axis Phonons in Fe-As Based Superconductors Investigated by Inelastic X-ray Scattering. https://arxiv.org/abs/0810.4941

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