Electron–phonon interaction in gallium point contacts
Annotatsiya
We report a study of point contacts fabricated of bulk gallium. We have studied the point contact function of the electron-phonon interaction for α-Ga, and we have calculated the electron-phonon interaction constant to be λ = 0.34±0.1. A number of the contacts contained inclusions of a metastable modification of gallium with a high Tc in the constriction region. Since all the measurements were carried out at temperatures above Tc for α-Ga, these structures may be denoted as point contacts of the type N–S–c–N or N–s–c–S–N. Measurements of the temperature dependence of the resistance of such contacts and studies of the subharmonic gap structure carried out on N–S–c–S–N contacts lead us to conclude that the superconducting clusters have the structure of the β-phase of gallium. We estimate the dimensions of such inclusions.