Title: Production and characterisation of strontium and magnesium doped lanthanum-gallium oxide (LSGM) ceramics

Authors: Hasan Erdem Camurlu, Filippo Maglia, Gaetano Chiodelli

Addresses: Mechanical Engineering Department, Akdeniz University, Dumlupinar Bulvari, 07058, Kampus, Antalya, Turkey. ' Physical Chemistry Department, University of Pavia, V.le Taramelli 16, 27100 Pavia, Italy. ' CNR-IENI, University of Pavia, V.le Taramelli 16, 27100 Pavia, Italy

Abstract: Strontium and magnesium doped lanthanum-gallium oxide (LSGM) ceramics exhibit high oxygen ionic conductivity at medium temperatures (800°C) as compared to other materials such as yttrium stabilised zirconia. Due to this property, they are candidates to be used as electrolyte materials in solid oxide fuel cells (SOFC). In this study, La0.80Sr0.20Ga0.83Mg0.17O3−δ and La0.90Sr0.10Ga0.80Mg0.20O3−δ powders were prepared from metal-nitrate starting materials by a Pechini type sol-gel process. Obtained powders were sintered at 1430°C for 24 hours in air. Powder X-ray diffraction and scanning electron microscopy analysis were performed on the powders and sintered ceramics and densities of the sintered ceramics were measured. Ceramics having single phase perovskite structure were produced with theoretical densities higher than 97%. LSGM ceramics were subjected to impedance spectroscopy analysis at 300°C, after coating with platinum. No grain boundary contribution was observed on the impedance of the ceramics. Ionic conductivities of the samples were measured in 400-1200°C range. At 800°C, the highest ionic conductivity value was measured as 0.14 S/cm, which was obtained in the La0.80Sr0.20Ga0.83Mg0.17O3−δ composition.

Keywords: impedance spectroscopy; strontium-magnesium doped lanthanum-gallium oxide; LSGM ceramics; Pechini type synthesis; electrolyte materials; solid oxide fuel cells; SOFC; sol-gel.

DOI: 10.1504/IJMMP.2009.031136

International Journal of Microstructure and Materials Properties, 2009 Vol.4 No.3, pp.301 - 310

Published online: 21 Jan 2010 *

Full-text access for editors Access for subscribers Purchase this article Comment on this article