Preparation of La2-x Sr x NiO4 (x = 0-1.3) conducting oxides via a citrate route

Abstract

La2-x SrxNiO4 (x = 0-1.3) oxide materials were prepared by the citrate and ceramic routes. The citrate precursors and final products were characterized by thermal analysis (DTA + TG), x-ray diffraction, scanning electron microscopy, IR spectroscopy, and specific surface and conductivity measurements. The use of citrate mixtures leads to the formation of amorphous precursors to La2O3, NiO, and La2-xSrxNiO4 (x <-0.4); reduces the temperature required for obtaining solid solutions by 150–200‡C as compared to the ceramic route; and enables the preparation of fine powders (≤5 Μm) and dense ceramics.