Effect of oxygen deficiency on the magnetic, electrical, and magnetoresistive properties of La0.7Sr0.3CoO3-delta

This study investigates the magnetic, electrical, and magnetoresistive prop erties of the oxygen-deficient compositions of La0.7Sr0.3CoO3-delta. Experi mental results indicate that the La0.7Sr0.3CoO3-delta (0 less than or equal to delta less than or equal to 0.15) compositions are all ferromagnetic an d exhibit a metal-insulator (M-I) transition. The magnetization decrease an d resistivity increase depend on the oxygen deficiency. Our results further suggest that the oxygen nonstoichiometry facilitates the cooling of the T- C and T-P. At a low temperature, the magnetoresistance depends heavily on m agnetization. A large MR effect is observed in a larger oxygen deficiency. Moreover, this study also discusses possible mechanisms.