Percolative nature of A-site disordered La0.75Ca0.25-xSrxMnO3 manganites

Abstract Magnetic, resistive, and magnetoresistance measurements were used to investigate the percolative nature of A-site disordered La 0.75 Ca 0.25−x Sr x MnO 3 (x = 0, 0.10) manganites. La 0.75 Ca 0.15 Sr 0.10 MnO 3 has an orthorhombic structure and second order magnetic phase transition indicates the presence of two prominent downturns T* and T ferro above the Curie temperature (T C ) in the derivative of the inverse susceptibility measurements. These observations are in agreement with the percolation model and the results are discussed in the light of phase separation happening in small polarons present in the insulating phase.