Epitaxial Growth of La_0.7Ba_0.3MnO₃ Thin Films on SrTiO₃ and LaAlO₃ Substrates by Metal-Organic Deposition

La_0.7Ba_0.3MnO₃ (LBMO) thin films were successfully prepared on SrTiO₃ (STO) and LaAlO₃ (LAO) single-crystal substrates by metal-organic deposition (MOD). The microstructure and the crystallinity of the LBMO films were examined in detail by high-resolution transmission electron microscopy and electron diffraction. The lattice mismatch between LBMO and STO is small as -0.1%; thus, the LBMO films were found to be epitaxially well grown. However, on the LAO substrate, which has a lattice mismatch of ∼-3.2% with LBMO, the films exhibited interfacial misfit dislocations along the interface. For an IR sensor application, we calculated the temperature coefficient of resistance (TCR) from the R(T) measurements. The films grown on STO substrates exhibited a TCR of approximately 5%/K at 306 K compared with 7%/K at 253 K exhibited by the films grown on LAO substrates.