Pulsed laser deposition growth and transport studies of superconducting La$_{1.85}$Y$_{0.15}$CuO$_{4}$ thin films

The recent MBE growth of the ``nominally undoped" cuprate superconductor (La,RE)$_{2}$CuO$_{4}$ has led to the speculation that this system is a band metal and not a ``doped Mott insulator" as found in all other superconducting cuprates $^1$. Here we report the first pulsed laser deposition (PLD) growth of insulating and superconducting La$_{1.85}$Y$_{0.15} $CuO$_{4}$ thin films, which are prepared under different oxygen conditions. We also report resistivity, Hall, Nernst, and magnetoresistance measurements, which show that La$_{1.85}$Y$_{0.15}$CuO$_{4}$ is an electron-doped, Mott-Hubbard system, where the carriers originate from oxygen nonstoichiometry produced by the oxygen reduction. This work is supported by NSF (DMR 0352735).\\ $^1$A. Tsukada et al., Sol. Stat. Commu. 133, 427 (2005).