Anisotropic resistance change of La0.7Sr0.3MnO3thin films effected by in-plane axial strain

Thin films of La0.7Sr0.3MnO3grown on (001) NdGaO3substrate using vertical hot wall Injection CVD reactor were investigated by means of standard fish-bellied beam inducing uniaxial compressive (or tensile) strain of the films. The measurements were carried out in current direction both parallel (longitudinal resistance R1) and perpendicular (transversal resistance R1) to the strain direction. The compression along [100], [110], [010] and [110] directions on films having 8 nm thickness showed the strong anisotropy of strain induced resistance change. The compression along [010] and [l10] directions caused the decrease of the film resistance while the compression along [100] and [110] directions increased this resistance. The maximum obtained relative resistance change was about 27% at strain 0.005. This effect appeared in both longitudinal and transversal directions of the electric current. The experimental results are discussed in terms of external strain influence on anisotropically strained La0.7Sr0.3MnO3film lattice produced as a result of large mismatch between substrate and film lattice constants.