EFFECT OF IMPURITY DOPING ON TC OF 123 SUPERCONDUCTORS

We have investigated the effect of substitution of magnetic impurities for copper in YBa2Cu3-xMxO7 (M = Fe, Co) superconductors by developing a Fourier transformed effective potential (FTEP), which involves the, influence of two dimensional (2D) acoustic phonons and plasmons. We have demonstrated that 2D acoustic plasmons have introduced 20-25% enhancement over the phonon contribution to the transition temperature (T(C)) at various compositions (x). Further, we have found that the increase in the values of the plasmon coupling parameter (lambda(pl) = 0.0 to 0.5) enhances T(C) from 70 to 300 K. These achievements clearly indicates that the inclusion of the effect of 2D acoustic plasmons is essential for proper description of the mechanism of high T(C) superconductivity.