Synthesis and characterization of lanthanum monoaluminate by co-precipitation method

摘要

Our contribution has focused on the synthesis and characterization of lanthanum monoaluminate LaAlO3 by the method of co-precipitation. The powder was successfully synthesized using NaOH, La (NO3)3.6H2O and Al (NO3)3.9H2O as raw materials by this method and calcined at different temperatures. It was characterized by several techniques: Fourier transform infrared spectroscopy (FT-IR), thermogravimetric and differential thermal analysis (TGA/DTA), X-ray diffraction (XRD) and laser diffusion. All the results for physico-chemicals characterizations show that the crystallization temperature of the LaAlO3 precursor gels precipitated is estimated as 790 °C by TG/DTA. The XRD pattern of the LaAlO3 precursor gels calcined at 700 °C for 6 h has a perovskite structure of rhombohedral hexagonal phase formed and the presence of crystalline impurities is not found. The crystallite size of LaAlO3 slightly increases from 31to 44.5 nm with calcination temperature increasing from 700to1000 °C for 6 h.Key words: Lanthanum monoaluminate / method of coprecipitation / thermal analysis / perovskite / rhombohedral hexagonal / LaAlO3