  We report resistivity, Hall effect, Nernst effect, and magnetoresistance
measurements on T'-phase La1.85Y0.15CuO (LYCO) films prepared by pulsed laser
deposition under different oxygen conditions. Our results show that
superconductivity in LYCO originates from an oxygen-doped Mott-like insulator
and not from a weakly correlated, half-filled band metal as proposed
previously.
