Anisotropic transport properties of single-crystal (La,Ca)MnOδ thin films

We report on the observation of anisotropic transport properties in La2/3Ca1/3MnOδ that has a nearly cubic perovskite structure. We prepared single-crystal La2/3Ca1/3MnOδ thin films with a-axis orientation. It is found that the resistivity and magnetoresistance of the samples annealed in oxygen at 920 °C for 1 h are higher along the c-axis direction than along the a-axis direction by about 34%–37% near the metal–semiconductor transition temperature. Further post-annealing in oxygen at 950 °C for 6 h increased the anisotropy ratio of magnetoresistance to 1.9. This indicates that the anisotropic transport properties result from additional magnetic scattering along the c-axis direction of the films.