Transport and magnetic properties of in situ grown thin-film La-Y-Ca-Mn-O

We report a large magnetoresistance in in situ grown La 0.60Y0.07Ca0.33MnOx thin films made at a low substrate temperature of 600°C without postdeposition annealing. The zero-field resistivity peaks around 120 K. The resistivity peak is reduced by two orders of magnitude by a 6 T field. Comparison of transport and magnetization data reveals a correlation of conductivity versus magnetization below the ferromagnetic transition temperature, which may suggest a double-exchange-based conduction mechanism. Above the ferromagnetic transition at low fields, a quadratic dependence of conductivity on magnetization is found, consistent with a spin-scattering-limited conductivity.© 1995 American Institute of Physics.