Effect of microstructure on electrical and mechanical properties of La5.4WO12-δ proton conductor. Issue 10 (August 2018)

• Record Type: Journal Article
• Authors: Deibert, Wendelin; Stournari, Vasiliki; Ivanova, Mariya E.; Escolástico, Sonia; Serra, José M.; Malzbender, Jürgen; Beck, Tilmann; Singheiser, Lorenz; Guillon, Olivier; Meulenberg, Wilhelm A.
• Is Part Of: Journal of the European Ceramic Society. Volume 38:Issue 10(2018)
• Page Start: 3527
• Page End: 3538
• Publication Date: 2018-08
• Subjects: Proton-Conducting ceramic membranes -- Lanthanum tungstate -- Mechanical properties -- Conductivity -- Strength -- Creep; Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2018.04.009
• Languages: English
• ISSNs: 0955-2219

Abstract

Abstract: The relationships between microstructural characteristics and electrical as well as mechanical properties of La5.4 WO12-δ (LWO54) materials were studied. Polycrystalline LWO54 samples revealed identical transport mechanisms regardless of the sample microstructure. The studied samples show predominately proton conductor behaviour below 800 °C and become predominant n-type and oxygen ion conductors above this temperature. The magnitude of the total conductivity is enhanced with larger grain size and lower porosity. Young's modulus decreased by 20% with increasing temperature up to 1000 °C regardless of grain size and atmosphere. Fracture strength was determined via ring-on-ring bending tests, yielding values that strongly depended on microstructural characteristics and homogeneity of the microstructure. Elevated temperature deformation studies revealed that creep is governed by cation diffusion mechanism.