Neutron scattering Measurements of the phonon density of states of FeSe$_{1-x}$ superconductors

TL;DR

This study uses inelastic neutron scattering to measure the phonon density of states in FeSe$_{1-x}$ superconductors, revealing a phonon cutoff around 40 meV and no change across the superconducting transition, supporting theoretical calculations.

Contribution

First experimental measurement of phonon density of states in FeSe$_{1-x}$ superconductors using neutron scattering, confirming theoretical predictions.

Findings

Phonon cutoff frequency around 40 meV.

No significant change across superconducting transition.

Supports first-principles calculations.

Abstract

Inelastic neutron-scattering experiments have been carried out on polycrystalline samples of the FeSe$_{1-x}$ superconductors. We report the phonon density of states for FeSe$_{1-x}$ with Tc$\approx$8 K. The phonon cutoff frequency is observed around 40 meV. No significant change is observed across the superconducting transition. The measurements support the published first-principles calculations [A. Subedi et al., Phys. Rev. B \textbf{78}, 134514 (2008)].