Composition dependence of transition temperature in some ceramic superconductors

Abstract

The composition dependence of transition temperature in some ceramic superconductors (La2-x (Ba, Sr)x CuO4) was studied by modifying our earlier approach and developing a Fourier-transformed effective potential which involves the effect of two-dimensional (2D) acoustic plasmons. This potential was used to obtain the pairing (electron-electron attraction) parameter (λ), the averaged Coulomb repulsive parameter (μ*) and the cut-off 2D acoustic plasmon frequency (ωc) required to compute the superconducting transition temperature (Tc) from the strong coupling theory. The variations of Tc with compositions (x) obtained for La2-x (Ba, Sr)x CuO4 show reasonably good agreement with experimental data. © 1993 Indian Academy of Sciences.