On the high-temperature superconductivity of Srx La 2−xCuO4−δ

The superconducting properties of Sr_xLa_2?xCuO_4?δ are analyzed by employing the model of interaction between charge carriers and the oxygen-displacive modes of the lattice. The role played by the hole concentration, as related to the Sr content x and oxygen deficiencyδ, is thoroughly emphasized. The critical temperature, the ratio of twice the superconducting gap to the critical temperature, and the isotope shift are estimated as functions of the hole concentration and compared with the experimental data.