Substrate-induced anomalous electrical transport and magnetic transitions in epitaxial La{sub}0.66Sr{sub}0.33MnO{sub}3 films grown of (001) BaTiO{sub}3 substrates

摘要

Effects of drastic change of 3-dimensional films' lattice strain by substrate structural transformations on the transport and magnetic properties of tensile strained epitaxial La{sub}0.66Sr{sub}0.33MnO{sub}3 thin films were studied using (001) BaTiO{sub}3 as the templates. These films exhibit dramatic jumps in electrical resistance and magnetization at temperatures very close to different crystallographic structural change of BaTiO{sub}3 substrate. Application of high magnetic field (50 kOe) suppresses both the electrical transport and magnetization jumps. The observed low-field sharp transitions correspond sudden changes in magnetic anisotropy, caused by the structural transformation of the substrate. The magnetic easy axis lies in the film plane along [100] direction having a strong correlation with the substrate-induced 3-dimensional strain states as determined by the normal and grazing incidence x-ray diffraction. The sudden substrate structural transformations imposes an additional drastic sharp change of the film strain which is found to reorient the magnetic easy axis within the film plane.