Structure and electrical properties in La2/3(Ca1−xSrx)1/3MnO3 films

The thin films of La2/3(Ca1−xSrx)1/3MnO3 (LCSMO) with x = 0, 1/3, and 2/3 through the Ca, Sr double-doping at A site of the La2/3A1/3MnO3 were prepared using the RF magnetron sputtering method. The X-ray diffraction patterns of the bulk samples show that with the increase of x, the structures exhibit the transition from the rhombohedral phase to the pseudo-cubic phase. The electrical properties show that these three thin films are the ferromagnetic and metallic state which can be fitted into the single magneton scattering formula: ρ(T) = ρ0 + aT2 at low temperature. The temperature range of the ferromagnetic metallic state becomes larger, and the peak resistivity temperature (Tp) increases with x. These can be qualitatively explained by the double exchange model.