Abstract
The lattice dynamics of Ba1-xKxFe2As 2 (x = 0.00, 0.27) have been studied by inelastic X-ray scattering measurement at room temperature. K doping induces the softening and broadening of phonon modes in the energy range E = 10 -15 meV. Analysis with a Born-von Kármán force-constant model indicates that the softening results from reduced interatomic force constants around (Ba, K) sites following the displacement of divalent Ba by monovalent K. The phonon broadening may be explained by the local distortions induced by the K substitution. Extra phonon modes are observed around the wave vector q = (0.5, 0, 0) at E = 16.5 meV for the x = 0.27 sample. These modes may arise either from the local disorder induced by K doping or from electron-phonon coupling.
Original language | English |
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Article number | 014714 |
Journal | journal of the physical society of japan |
Volume | 79 |
Issue number | 1 |
DOIs | |
Publication status | Published - Jan 2010 |
Externally published | Yes |
Keywords
- Fe-based superconductor
- Inelastic X-ray scattering
- Phonon dispersion
ASJC Scopus subject areas
- Physics and Astronomy(all)