Perovskite Oxide LaCoO3 Prepared by Solid-state Reaction, Pyrolysis of a Co-Precipitated Precursor or Pyrolysis of a Heteronuclear Complex.

Abstract

The perovskite oxide LaCoO3 was synthesized by three different preparative methods i.e., the calcination of a mixture of La2O3 and CoO (La–Co–O) and pyrolysis of a co-precipitated precursor (La–Co–ox), La2 (C2O4)3 · xH2O + CoC2O4 · yH2O, and a heteronuclear complex (La–Co–CN), La[Co(CN)6] · 5H2O. The obtained powders were characterized by thermogravimetric analysis, infrared spectroscopy, powder X-ray diffraction, scanning electron microscopy and specific surface area measurements. The formation of LaCoO3 single phase is clearly recognized for La–Co–O, La–Co–ox and La–Co–CN at temperatures above 1000, 1200 and 600 °C, respectively. The nano-sized LaCoO3 powder was obtained at low temperatures by pyrolysis of La–Co–CN. The mean particle diameter of La–Co–CN calcined at 600 °C for 2 h was 72 nm.