Charge inhomogeneities in La2/3Ca1/3MnO3 epitaxial thin films

Abstract We present and compare here transport measurements on epitaxial thin films of La 2/3 Ca 1/3 MnO 3 grown by sputtering and MOCVD on SrTiO 3 substrates. As-grown sputtered films exhibit depressed magnetic and transport properties when compared with MOCVD samples, but both magnetic transition temperature, T C , and saturation magnetization, M S , may be substantially improved by annealing samples in air. A transverse voltage drop is measured across a patterned measuring track with a temperature dependence that, particularly around T C , cannot be explained in terms of the longitudinal resistance component alone. High temperature annealing substantially suppress these features as well as the application of high magnetic fields. We argue that these effects reflect inhomogeneous current flow, likely to be related with charge inhomogeneities and electronic phase segregation.