Synthesis, structures, and physical properties of yttrium-doped strontium manganese oxide films

Cubic strontium manganese oxide is an end-member of the colossal magnetoresistive (CMR) family of manganese-based perovskites, Ln(1-x)AE(x)MnO(3). Because normal synthesis conditions lead to the 4-H hexagonal polymorph, high-pressure conditions are typically used to obtain the cubic perovskite polymorph. In this work, we describe the synthesis and structural/physical characterization of the cubic perovskite form of the high-alkaline-earth containing phases of Y1-xSrxMnO3 (x greater than or equal to 0.7) as epitaxial thin films. Thin films of various stoichiometries were grown on single-crystal perovskite substrates SrTiO3, NdGaO3, and LaAlO3 using pulsed laser deposition. After optimizing deposition conditions, the perovskite polymorph is obtained using PLD at 800degreesC and 10-100 mTorr O-2 for x=1, 0.9, 0.8, and 0.7, as demonstrated by x-ray diffraction. Epitaxial growth was determined to be cube-on-cube. Electrical property measurements demonstrated insulating behavior and no metal-insulator transition or magnetoresistive behavior, similar to related stable compounds.