Microstructures of lanthanum nickel oxide particles with crystal facets synthesized in molten chlorides

Abstract

LaNiO₃ cuboid particles were successfully synthesized by the sol–gel method in the presence of molten chlorides. The precursor gels derived from the La(NO₃)₃ and Ni(CH₃COO)₂ solution were heated with molten chloride, NaCl or KCl, above the melting point of respective molten salts. The formation reaction of LaNiO₃ was completed below the melting point of these chlorides, and then crystal growth process might be facilitated in liquid phase provided by the molten chlorides due to an increase in the mass-transportation rate. The formation of the submicron to micron-sized LaNiO₃ cuboid particles, which are enclosed by {100} facets of pseudocubic perovskite, is confirmed by the electron microscope observations and the electron diffraction analysis.