Low-field magnetoresistance of La0.7Sr0.3MnO3 thin films with gradually changed texture

A gradual change of the grain orientation with the substrate temperature ${\mathrm{(T}}_S)$ during deposition has been observed for ${\mathrm{La}}_{\mathrm{0.7}}{\mathrm{Sr}}_{\mathrm{0.3}}{\mathrm{MnO}}_{\mathrm{3}}$ films on Y-stabilized ${\mathrm{ZrO}}_{\mathrm{2}}\text{(100)}$ substrates. Epitaxial growth has been found around $T_S\text{≈800\hspace{0.17em}}\mathrm{°C}.$ Both the low-field and the high-field magnetoresistance (MR) observed for the ferromagnetic state of these polycrystalline colossal MR manganite films were found to systematically depend on the degree of texture. The experimental results suggest a crucial role of a highly resistive region at the grain boundaries for this MR effect.