Preparation of nanosized perovskite LaNiO3 powder via amorphous heteronuclear complex precursor

Nanosized lanthanum nickel oxide powder LaNiO₃ with perovskite structure was successfully synthesized at a relatively low calcination temperature by using an amorphous heteronuclear complex LaNi(DTPA) · 6H₂O as a precursor. The precursor decomposed completely into nickel oxide above 600°C based on the DTA and TGA results. XRD demonstrated that nanosized LaNiO₃ crystalline powder with pure perovskite structure was obtained after the calcination temperature increased to 700°C. The effects of calcination time and temperature were also examined by XRD and TEM. The results indicated the grain size and the crystal size of LaNiO₃ increased with the calcination temperature from 600°C to 900°C, and were less influenced by the heat-treatment time. The electrical resistivity of the powder decreased when the calcination temperature increased. It can be concluded that it is a useful way to synthesize nanosized perovskite oxides using an amorphous complex as a precursor, and this method can be easily quantitatively controlled.