New superconducting PbSr2CuO5+delta prepared by a novel low-temperature synthetic route using molecular beam epitaxy

We report the synthesis of a new superconducting cuprate PbSr2CuO5+delta (T -c similar to 40 K) by a novel low-temperature synthetic route using molecu lar beam epitaxy. The new superconductor is the first member of the (Pb-12( n-1)n) homologous series, which contains a single PbO layer as the charge r eservoir block. Low temperature synthesis by molecular beam epitaxy (MBE) a nd an appropriate choice of lattice-matched substrates are essential to our discovery of PbSr2CuO5+delta superconductor. This work demonstrates that M BE opens up a novel synthetic route for new cuprates.