La0.8sr0.2cr0.5fe0.5o3- Δ  (Lscf) Synthesized by Molten Salt Method

Abstract

La0.8Sr0.2Cr0.5Fe0.5O3-δ was synthesised by the molten salt method using NaCl and KCl as the molten salt medium. The specimens were analysed by XRD, SEM, TG and DSC. The results are listed as follows. Firstly, all of them have orthorhombic crystalline perovskite structure under the conditions of 1000-1200 °C; the optimum temperature and holding time for the synthesis of La0.8Sr0.2Cr0.5Fe0.5O3-δ by the molten salt method is 1100°C for 3 hours. Secondly, the thermal and kinetic analysis allow the synthesis of La0.8Sr0.2Cr0.5Fe0.5O3-δ to be divided into three stages, with the first phase being the decomposition of La(OH)3, the second phase being the synthesis of LaFeO3, and the third phase being the synthesis of La0.8Sr0.2Cr0.5Fe0.5O3-δ, with the activation energies of 0.4408 (KJ·mol-1), 0.1188 (KJ·mol-1), and 0.3631 (KJ·mol-1). Finally, the synthesis mechanism of La0.8Sr0.2Cr0.5Fe0.5O3-δ powder synthesized by molten salt method is "dissolution-precipitation".

Keywords: Molten salt methodMicrostructureThermal analysis kineticsSynthesis mechanism