Microstructural Aspects of Cation Interdiffusion Across the LSCF/GDC Interface

Abstract

To evaluate the long-term durability of a reaction barrier made of gadolinium doped ceria (GDC), we have measured cation diffusion in the LSCF/GDC system. Interdiffusion and microstructural evolution were investigated for samples annealed at temperatures of 1000 to 1200 oC and times from 30 to 672 h. Significant diffusion of lanthanum into GDC and diffusion of ceria and gadolinium into LSCF were observed. X-ray diffraction (XRD) revealed the formation of lanthanum doped ceria (LDC) in the vicinity of the interface. Furthermore, EDS analysis showed the uneven distribution of lanthanum into the polycrystalline ceria. Those compositional patched patterns are thought to be the result of the interplay of diffusion along grain boundaries and bulk diffusion, without excluding the possible effect of crystallographic relationship at the interface.