On the Change of the Transition Temperature of Ordinary Superconductors

An expression, valid under an arbitrary phonon dispersion law omega(q), is analytically derived for the critical temperature of ordinary superconductors with weak coupling. The critical temperature T-c turns out to be strongly dependent on the nature of the phonon spectrum. The effect of the dispersion law omega(q) on the dependence of T-c on the electron concentration n is investigated. The existence of a maximum of the function T-c(n) is shown to be a possibility. The likelihood of observing nonphonon mechanisms of superconductivity is discussed.