Effect of oxygen deficiency (δ) on normal state resistivity of YBa2Cu3O7-δ superconductors

Abstract

We have investigated theoretically the effect of oxygen deficiency (δ) on normal state resistivity (δ) as well as its temperature dependence in YBa2Cu3O7-δ superconductors. This has been based on a potential which incorporates the structure factors and various interactions for double two-dimensional (2-D) conducting CuO2 plane. Using the Coulomb and electron-phonon terms of the interaction potential, we have then worked out the coupling strength (γ) for neighbouring electrons linked via 2-D acoustic phonons (hω). Furthermore, the scattering time (τe-ph) due to electron-phonon interaction is deduced. The variations in τe-ph and pe-ph are studied with oxygen deficiency (δ) which is in the range of 0·0 ≤ δ ≤, 1·0, and the results thus obtained are found to be consistent with the earlier reported data. The residual resistivity po obtained by extrapolation from experimental data together with pe-ph will predict the nearly-linear behaviour of normal state resistivity at temperatures (T) [90 ≤ T ≤ 300K] in YBa2CU3O7-δ superconductors.