Angular dependence of tunneling magnetoresistance in La0.7Sr0.3MnO3 step-edge junctions

La0.7Sr0.3MnO3 (LSMO) tunneling magnetoresistance (TMR) junctions have been fabricated on step-edge (0 0 1) SrTiO3 substrates with a high step-edge angle. In the measurement of magnetoresistance (MR) ratio versus external magnetic field H, butterfly-like MR curves are clearly observed. The MR(H  ) curves vary with θθ, the angle between the applied magnetic field and the current direction in the substrate plane, showing anisotropic MR properties. A much broader MR(H) response is observed for the configuration of H perpendicular to the substrate plane. Additionally, the maxima-MR field Hp almost coincides with the coercive field Hc for θ<60°θ<60° but obeys a different form from Hc(θ)Hc(θ). The high-field junction resistance shows an intrinsic sin2θsin2θ angular dependence, while the low-field resistance shows an extrinsic cos(4θ)cos(4θ) angular dependence. The distinctive features are mainly due to the induced magnetization anisotropy in the artificial steps of grain boundaries.