Reentrant insulating state in ultrathin manganite films

The transport and magnetic properties of La(0.7)Sr(0.3)MnO(3) thin-films grown by pulsed laser deposition on (LaAlO(3))(0.3)(SrAl(0.5)Ta(0.5)O(3))(0.7) single crystal substrates have been investigated. A systematic series with various thicknesses of La(0.7)Sr(0.3)MnO(3) was used to establish a phase diagram which showed a clear difference compared to films grown on SrTiO(3) substrates, highlighting the importance of film thickness, and substrate strain. At 8 unit cells, the boundary between the metallic and insulating groundstates, a second abrupt metal-insulator transition was observed at low temperatures, which could be tuned by magnetic field, and was interpreted as a signature of electronic phase separation. (C) 2011 American Institute of Physics. [doi:10.1063/1.3628659]