Structural, electrical and magnetic properties of perovskites La0.67Ca0.33Mn1−xCoxO3 (0.5⩽x⩽1)

Abstract Polycrystalline perovskite La 0.67 Ca 03.3 Mn 1− x Co x O 3 (0.5⩽ x ⩽1) system was studied by electrical resistivity, magnetization, and AC susceptibility measurements. The structure and lattice parameters were determined by X-ray powder diffraction. The data suggest the presence of correlated magnetic clusters at low temperatures as was shown from the AC susceptibility and from nonlinear AC susceptibility measurements. The electrical behavior can be explained by hopping of the carriers in a Co 3+ matrix in the presence of a disproportionation effect in the high-temperature region.