Syntheses and magnetic properties of La1-xSrxMnOy (0.5≤x≤1.0) perovskite

La1-xSrxMnOy with 0.0 less than or equal to x less than or equal to 0.6, which reveals very interesting physical properties such as ferromagnetism and metallic resistivity, can easily be synthesized by the conventional solid state reaction. In the case of the composition of x > 0.6, they cannot be synthesized by the normal synthesis but by the two-stage solid state reaction, which at first makes the oxygen-deficient state at high temperature and then inserts oxygen by O-2 annealing at low temperature. Nevertheless all of obtained compound is single phase cubic perovskite structure, ferromagnetism and metallic property observed in the composition range 0.175 less than or equal to x less than or equal to 0.6 are not revealed, cause of drastic change between 0.50 < x < 0.60. (C) 1999 Academic Press.