Superconductivity and Electron-Phonon Interaction in Cu0.5Tl0.5Ba2Ca2Cu3-y M y O10-δ (M=0, Si, Ge, Sn, and y=0, 1)

Superconducting properties of Cu0.5Tl0.5Ba2Ca2Cu3-y M (y) O10-delta (M=0, Si, Ge, Sn and y=0, 1) samples have been studied by using x-ray diffraction (XRD), resistivity, ac-susceptibility and Fourier Transform Infrared (FTIR) absorption measurements. We have tried to explore the role of the electron-phonon interaction in bringing about superconductivity in the Cu0.5Tl0.5Ba2Ca2Cu3-y M (y) O10-delta material. A change in the cell parameters from XRD and the change in the shape of FTIR absorption spectra have shown the incorporation of doped elements (M=Si, Ge, Sn) in the unit cell of the final compound. It is most likely that the change in oxygen phonon modes is associated with the oscillations of heavier and lighter atoms in MO2/CuO2 planes. These oscillations of heavier and lighter atoms suppress the density of the phonon population from the desired level for optimum superconductivity in the final compound.