Microstructural and electrical properties of $La0.7Ca0.3MnO3$ thin films grown on $SrTiO3$ and $LaAlO3$ substrates using metal-organic deposition Available to Purchase

$La0.7Ca0.3MnO3$ (LCMO) thin films have been prepared on $LaAlO3$ and $SrTiO3$ (STO) (001) single-crystal substrates by the metal-organic deposition process. These films were characterized by transmission electron microscopy (TEM) and temperature dependence of the resistance $R(T)$⁠. The microstructure of the LCMO films and LCMO/substrate interfaces were investigated through cross-sectional TEM observations. High-resolution TEM (HRTEM) observations and electron-diffraction patterns demonstrate the (001) epitaxial growth on both the LAO and STO substrates. The local structure of the LCMO film depends on the type of substrate. HRTEM observations along the LCMO/STO interface display a good epitaxy throughout the entire film without any microstructural defects. On the contrary, in the LCMO film and in the region close to the LAO substrate, we note the presence of misfit dislocations and twins. The temperature coefficient of resistance (TCR) was calculated from the temperature dependence of the resistance measurements. The LCMO/LAO system exhibits a TCR value of $27.5%∕K$ compared with the $10%∕K$ measured for the LCMO/STO system.