Evolution and sign control of square-wave-like anisotropic magneto-resistance in spatially confined La_0.3Pr_0.4Ca_0.3MnO₃/LaAlO₃(001) manganite thin films

We investigated magneto-transport properties of a compressively strained spatially confined La_0.3Pr_0.4Ca_0.3MnO₃ (LPCMO) thin film micro-bridge deposited on LaAlO₃. Angular dependence of the magneto-resistance R(θ) of this bridge, where θ is the angle between the magnetic field and the current directions in the film plane, exhibits sharp positive and negative percolation jumps near T_MIT. The sign and the magnitude of these jumps can be tuned using the magnetic field. Such behavior has not been observed in LPCMO micro-bridges subjected to tensile strain, indicating a correlation between the type of the lattice strain, the distribution of electronic domains, and the anisotropic magneto-resistance in spatially confined manganite systems.