Low-Temperature Synthesis of La₂Ti₂O₇ Nanocrystal by Metallorganic Decomposition Method

Abstract

Nanopowders of La₂Ti₂O₇ have been successfully prepared by metallorganic decomposition method (MOD). In comparison with the higher reaction temperature of conventional preparation methods, such as solid-state reaction (about 1100°C), the nanocrystal La₂Ti₂O₇ phase can be formed at an evidently lower temperature of 700°C by MOD. The resulting powders exhibit small and uniform grains. The imagines of FT-IR show that acetylacetone can associate with La³⁺ to form La-acetylacetone chelate complexes, and the absorption peak of La³⁺ in precursor solution disappears, while the peaks of chelate complexes located at 1580 and 1420 cm^-1 are found correspondingly. The probable reason is that small precursor particles can be formed at a homogeneous and low La³⁺ concentration by control release from the complexes; these small, uniform and more active precursor particles probably make it possible to form La₂Ti₂O₇ nanocrystal at significantly lower preparation temperature.