LaNiO3 nanopowder prepared by an ‘amorphous citrate’ route

Aqueous solution techniques are simple and easy to use technological methods for preparing single-phase ceramic powders with controlled and homogeneous grain size. This study presents the preparation of ferroelectric LaNiO3 ceramic samples by a gel-method using low sintering temperatures and the evolution of the amorphous complex and LaNiO3 nanocrystallites with temperature.Ferroelectric LaNiO3 powders were prepared using an ‘amorphous citrate’ route. X-ray diffraction, Raman scattering and electron microscopy techniques were used to characterize the obtained products after thermal treatments at between 550 and 750 °C and revealed the formation of LaNiO3 nanocrystallites of perovskite structure with homogeneous grain size after thermal treatment at 650, 700 and 750 °C, with particle sizes of ∼30, 42 and 65 nm, respectively. Raman spectra exhibit the characteristic band of the LaNiO3 perovskite-phase at 392 cm−1 and decreasing band width with temperature, an effect associated to the observed change in grain size.