Enhanced magnetoresistance in strain-free manganite network

A network structure of a ferromagnetic metallic (FMM)/charge-ordered insulator (COI) mixed phase manganite has been obtained by annealing a 150 Angstrom Pr-0.65(Ca0.75Sr0.25)(0.35)MnO3 film under tensile strain on a SrTiO3 substrate. Under the same deposition and annealing conditions, a film deposited on a LaAlO3 substrate, which provides compressive strain, remains continuous. The network structure also manifests a larger magnetoresistance than the continuous film. It is suggested that the lateral confinement in this filamentary structure may affect the percolative transport in this mixed FMM/COI system. (C) 2005 American Institute of Physics.