2 research outputs found
Electron-phonon coupling and superconductivity in -MoB as a function of pressure
We have studied the lattice dynamics, electron-phonon coupling, and
superconducting properties of -MoB, as a function of applied
pressure, within the framework of density functional perturbation theory using
a mixed-basis pseudopotential method. We found that phonon modes located along
the AH, HL, and LA high-symmetry paths exhibit large phonon linewidths
and contribute significantly to the electron-phonon coupling constant. Although
linewidths are particularly large for the highest-frequency optical phonon
modes (dominated by B vibrations), their contribution to the electron-phonon
coupling constant is marginal. The latter is largely controlled by the acoustic
low-frequency modes of predominantly Mo character. It was observed that at a
pressure of ~GPa, where -MoB forms, the phonon-mediated pairing
falls into the strong-coupling regime, and the estimate for the superconducting
critical temperature agrees well with experimental observations. When
further increasing the applied pressure, a reduction of is predicted,
which correlates with a hardening of the acoustic low-frequency phonon modes
and a decrease of the electron-phonon coupling parameter.Comment: Updated and accepted for publication versio