Magnetotransport in manganite trilayer junctions grown by 90° off-axis sputtering

We report magnetotransport studies on La0.67Sr0.33MnO3/SrTiO3/La0.67Sr0.33MnO3 trilayer junctions, fabricated using 90 degrees off-axis sputtering. Films were grown on both (001) (LaAlO3)(0.3)-(Sr2AlTaO6)(0.7) and (110) NdGaO3 substrates. The sputtered trilayers show improved junction resistance uniformity over those made using pulsed laser deposition. Cross-sectional transmission electron microscopy and atomic force microscopy studies confirm smooth interfaces and a uniform barrier. Magnetoresistances up to similar to 100% are observed for junctions on (001) (LaAlO3)(0.3)-(Sr2AlTaO6)(0.7) with a 30 Angstrom barrier at 13 K and around 100 Oe. Junction magnetoresistance versus magnetic field behavior is more stable, indicating improved transport and magnetic homogeneity across the junction. (C) 2001 American Institute of Physics.