Magneto-transport properties of La0.7Sr0.3MnO3–manganese oxide composite films on YSZ substrates prepared using aerosol deposition

We report the magneto-transport properties of pure La0.7Sr0.3MnO3 (LSMO) and 40 mol% LSMO–Mn3O4 (LSMM) composite films on YSZ (yttrium stabilized zirconia) substrates prepared using aerosol deposition (AD). As-deposited films via AD were post-annealed at 1100 °C and 1200 °C for 2 h in air. While the as-deposited films commonly exhibited a poor low-field magnetoresistance (LFMR) property with reduced Curie temperatures (Tc), post-annealed films exhibited a very good LFMR property with high Tc values ranging from 355 to 370 K. The highest LFMR value of 1.2% in 0.5 kOe and an unprecedentedly high (dMR/dH)max value of 158.8%kOe−1 were obtainable at 300 K from the LSMM composite film annealed at 1200 °C. Compared with a pure LSMO film, the LSMM composite films possess higher LFMR values with higher (dMR/dH)max values, which is primarily attributed to a greatly reduced magnetically disordered region near the LSMO grain boundary because of the chemically compatible Mn3O4 phase.