Abstract
We report an inelastic neutron scattering investigation of phonons with energies up to 159 meV in the conventional superconductor . Using the sweep mode, a newly developed time-of-flight technique involving the continuous rotation of a single crystal specimen, allowed us to measure a four-dimensional volume in (, ) space and, thus, determine the dispersion surface and linewidths of the () and () type phonon modes over the whole Brillouin zone. Despite of having linewidths of , modes do not strongly contribute to the total electron-phonon coupling constant . However, experimental linewidths show a remarkable agreement with ab initio calculations over the complete phonon energy range, demonstrating the accuracy of such calculations in a rare comparison to a comprehensive experimental data set.
- Received 21 November 2011
DOI:https://doi.org/10.1103/PhysRevLett.109.057001
© 2012 American Physical Society