Percolative conductivity in the La0.67Sr0.33Mn1-xMgxO3 system -: art. no. 092407

The effects of Mg substitution on a Mn site have been studied in the series perovskite manganites La0.67Sr0.33Mn1-xMgxO3 (0.0less than or equal toxless than or equal to0.20). With increasing Mg content, the decrease of the magnetization, the widening of the paramagnetic-ferromagnetic transition, and the appearance of the cluster-spin-glass state have been observed. With decreasing temperature, all samples display a paramagnetic-ferromagnetic transition associated with the insulator-metal transition in the low doping region, but without the insulator-metal transition in the heavily doping zone. The phase separation in these doped samples results in the percolative conductivity.