Structure and magnetotransport properties of epitaxial nanocomposite La 0.67 Ca 0.33 MnO 3 :SrTiO 3 thin films grown by a chemical solution approach

Epitaxial La 0.67 Ca 0.33 MnO 3 :SrTiO 3 (LCMO:STO) composite thin films have been grown on single crystal LaAlO 3 (001) substrates by a cost effective polymer-assisted deposition method. Both x-ray diffraction and high-resolution transmission electron microscopy confirm the growth of epitaxial films with an epitaxial relationship between the films and the substrates as (002) film ||(002) sub and [202] film ||[202] sub . The transport property measurement shows that the STO phase significantly increases the resistivity and enhances the magnetoresistance (MR) effect of LCMO and moves the metal-insulator transition to lower temperatures. For example, the MR values measured at magnetic fields of 0 and 3T are −44.6% at 255K for LCMO, −94.2% at 125K for LCMO:3% STO, and −99.4% at 100K for LCMO:5% STO, respectively.