Point contact spectroscopy in Ga single crystals

The current-voltage characteristics of point contacts in Ga single crystals have been measured in the liquid helium temperature range. At least six singular structures were found in energy range between 6 to 31 mV of the spectra d²V/dI². They are in good agreement with the structure of the phonon density-of-states determined from the inelastic neutron scattering experiment by Reichardt et al. The obtained spectra were used to estimate the electron-phonon coupling parameter.