Interactions between components of SrTi_0.98Nb_0.02O_3−δ–YSZ and SrTi_0.98Nb_0.02O_3−δ–CeO₂ composites

Abstract

Composites consisting of SrTiO 3 -based perovskite and either yttria-stabilized zirconia or ceria were investigated. The mechanical compatibility and possible inter-diffusion between phases were characterized by scanning electron microscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy. A gradual disappearance of Ce-containing phases with an increase in the temperature of reduction in hydrogen was noticed. Moreover, a diffusion of Sr, Ti, and Ce was observed between the composites and the yttria-stabilized zirconia electrolyte support in the conditions of high temperature (1300-1400 8C) reduction in H 2 .

Correlation between structural and electrical properties in highly porous (Y,Sr)(Ti,Nb)O3−δ SOFC anodes

“…The 7 -8 % decrease of σ value after 30 h was observed for both samples [26]. According to above results and previous papers [23,30] it can be concluded that STN2 and YSTN7 samples have sufficient chemical stability to use them as SOFC anodes.…”

“…When considering STN2 and YSTN7 samples as SOFC anodes it is necessary to analyze their electrical stability in a fuel atmosphere (H 2 ) and its reactivity with an electrolyte. The reactivity of STN2 material with the YSZ electrolyte has been previously analyzed by the SEM-EDX technique [23,30]. It has been shown [23,30] that a diffusion process of titanium and strontium cations into YSZ takes place and this phenomenon can result in a decrease of efficiency of the SOFC.…”

“…The reactivity of STN2 material with the YSZ electrolyte has been previously analyzed by the SEM-EDX technique [23,30]. It has been shown [23,30] that a diffusion process of titanium and strontium cations into YSZ takes place and this phenomenon can result in a decrease of efficiency of the SOFC. However, it was reported [30] that the additional functional layer of STN2-YSZ between an anode and electrolyte can overcome this process.…”

“…It has been shown [23,30] that a diffusion process of titanium and strontium cations into YSZ takes place and this phenomenon can result in a decrease of efficiency of the SOFC. However, it was reported [30] that the additional functional layer of STN2-YSZ between an anode and electrolyte can overcome this process. Additionally, the forced nonstoichiometry in strontium site (Sr-deficiency) can significantly reduce the undesired Sr-diffusion into YSZ [23].…”

Conductivity and structure of sub-micrometric SrTiO3–YSZ composites

“…Despite the current disagreement on the nature of the conductivity in SrTiO3-YSZ interfaces there is further interest on composites of these two materials as they represent alternative anodes for fuel cells: SrTiO3 can exhibit high electronic conductivity achieved by suitable doping and high temperature reduction treatment (>1300 o C) [8,9,10].…”