POSITRON DISTRIBUTIONS AND LIFETIMES IN NOVEL SUPERCONDUCTORS

We have calculated positron distributions and lifetimes in novel superconductors and related materials using the superposed-atom model and the numerical relaxation technique. Both delocalized and trapped states of positrons are investigated for infinite-layer compound SrCuO2 and alkali- or alkaline-earth-doped C60. Calculations are also performed for delocalized states in BEDT-TTF based organic conductors. Results are discussed in terms of Fermiology and defect spectroscopy by positron annihilation techniques.