Impurity mechanism for high-temperature superconductivity and features of the IR spectra of metal oxides

This paper interprets features of the IR spectra of metal oxides on the basis of an impurity mechanism for high-temperature superconductivity proposed earlier. The appearance of a Lorentzian oscillator line in the middle of the IR region, its weak temperature dependence, and the absence of a shift of the maximum of this line as the impurity concentration varies can be explained, as well as the dependence of the oscillator strength on the stoichiometric composition and the frequency and temperature dependence of the Drude contribution. It is shown that the gap is determined by the onset frequency at which the Lorentzian oscillator line appears in the low-frequency region, as well as by the frequency, which coincides with this, at which the optical conductivity appears when T < Tc. 29 refs., 4 figs., 2 tabs