Abstract
The properties of screened plasma oscillations of the d band, which Fröhlich first suggested could lead to superconductivity, are investigated. Specific-heat anomalies in the normal and superconducting state, normal-state resistivities, pressure-induced and pressure-dependent superconductivity, Mössbauer-effect studies, lattice transformations, and the occurrence of superconductivity in transition metals are compared with the theory. These diverse properties indicate that the Fröhlich mechanism is operative in high-Tc transition elements and constitutes a new mechanism for superconductivity.