Preparation of nanosized La 1− xSr xCoO 3 via La 1− xSr xCo(DTPA)·6H 2O amorphous complex precursor

Abstract

Nanosized La 1− x Sr x CoO 3 ( x=0.05, 0.1, 0.6) cobalite oxide powder with perovskite structure was successfully synthesized at a relatively low calcination temperature by using an amorphous heteronuclear complex La 1− x Sr x Co(DTPA)·6H 2O as a precursor. The precursor decomposed completely into cobalite oxide above 600 °C based on the differential thermal analysis (DTA) and thermal gradient analysis (TGA) results. X-ray diffraction (XRD) demonstrated that nanosized La 1− x Sr x CoO 3 crystalline powder with perovskite structure was obtained after the calcination temperature increased to 600 °C. The effects of calcination time and temperature were also examined by XRD and transmission electron microscopy (TEM). The results indicated that the grain size and the crystal size of La 1− x Sr x CoO 3 increased with the calcination temperature from 600 to 800 °C, and were less influenced by the heat-treatment time. It can be concluded that it was a useful way to synthesize nanosized perovskite oxides using an amorphous complex as a precursor, and this method can be easily quantitatively controlled.