Electron transport and magnetic properties of La1−xSrxCo1−yTiyO3 (x = 0a or x = yb)

The two systems (a) and (b) for different values of x were synthesized. Their electron transport and magnetic properties show a change in behavior above a critical value of x. Unlike the system La_1?xSr_xCoO₃, itinerant electron ferromagnetism is not observed. This is explained on the basis of the absence of an itinerant band of Co⁴⁺ whose generation is restricted on account of substitution of Ti⁴⁺. Electron transport in these two systems is compared with that of LaCoO₃ or La_1?xSr_xCoO₃ and is discussed in view of the presence of different valence states of cobalt and change in crystal field splitting. Spin-state equilibria in these two systems are similar to that in LaCoO₃.