INELASTIC LIGHT-SCATTERING FROM ELECTRONIC AND PHONONIC EXCITATIONS IN NORMAL AND SUPERCONDUCTING TL2BA2CUO6 SINGLE-CRYSTALS

We report results of Raman-scattering experiments on electronic and phononic excitations in single-crystalline Tl2Ba2CuO6 with one Cu-O layer and a T(c) of 80 K. The electronic scattering is similar to that in other Cu-O compounds, revealing a symmetry-dependent carrier relaxation rate above T(c) and a characteristic redistribution of scattering intensity below T(c). The maximum pairing energy 2DELTA0 estimated from the spectra is between 8 and 9kT(c). In addition to the Raman-allowed phonons several new lines and bands are found which we believe to originate from the reduced symmetry of the Tl-O layers. The intensities of all phonon lines depend sensitively on the excitation wavelength.