Author/Authors :
Mathieu Le Tacon، نويسنده , , T.R. Forrest، نويسنده , , Ch. Rüegg، نويسنده , , A. Bosak، نويسنده , , J. Noffsinger، نويسنده , , A.C. Walters، نويسنده , , P. Toulemonde، نويسنده , , A. Palenzona، نويسنده , , N.D. Zhigadlo، نويسنده , , J. Karpinski، نويسنده , , J.P. Hill، نويسنده , , M. Krisch، نويسنده , , D.F. McMorrow، نويسنده ,
Abstract :
We report measurements of the phonon density of states as probed with inelastic X-ray scattering in SmFeAsO1−xFy powders. An unexpected strong renormalization of phonon branches around 23 meV is observed as fluorine is substituted for oxygen. Phonon dispersion measurements on SmFeAsO1−xFy single crystals allow us to identify the 21 meV A1g in-phase (Sm,As) and the 26 meV B1g (Fe,O) modes to be responsible for this renormalization, and may reveal unusual electron–phonon coupling through the spin channel in iron-based superconductors.
