Evidence of Electron–Phonon Interaction in Al-Substituted Mg1-xAlxB2

Abstract

Phonon density of states in Al substituted Mg 1-x Al x B 2 has been studied by means of inelastic neutron scattering experiments with pulsed neutron time-of-flight technique. Phonon dynamics have a significant role for realizing superconductivity in the recent discovered superconductor MgB 2 . We present a systematic investigation on generalized phonon density of states (PDOS) up to E = 120 meV on Al content of x = 0.1, 0.25, and 0.5. We have clearly observed a large effect on the PDOS by Al substitution; a large energy shift occurs around at 70 meV and 89 meV. We have also observed a visible increase of PDOS at a particular energy range below T c . Those phonon states are related with E 2g mode to be expected to have a strong coupling with the electron states at the r-A region.