Preparation and characterization of Yb-doped Ba(Ce,Zr)O3 nanopowders with high sinterability

Abstract

The Ba(Ce 0.8 Zr 0.2 ) 0.95 Yb 0.05 O 2.975 ceramics electrolyte was prepared via a Pechini method using metal nitrate salts as starting materials. An optimum annealing temperature of 1,400°C was needed to obtain a pure perovskite-like phase with orthorhombic structure. Particle size distribution showed a bimodal distribution that corresponds to the loose powders and agglomerates size. Scanning electron micrograph revealed that the loose powders were in the nanosize range (70-200 nm). These ultrafine loose powders enhanced the densification of a pellet with relative density ∼95% obtained at 1,400°C. The sample formed clear and compact grains with submicron sizes. Impedance results showed that the impedance semicircle of the grain was observed only at T≤250°C. The introduction of 20 mol% Zr improved the chemical stability of BaCe 0.95 Yb 0.05 O 2.975 sample in atmosphere containing carbon dioxide at 600°C. The sample also exhibited high proton conductivity in wet hydrogen.

Effect of strontium on Nd doped Ba 1− x Sr x Ce 0.65 Zr 0.25 Nd 0.1 O 3− δ proton conductor as an electrolyte for solid oxide fuel cells

“…The assignment mode of the bands of sintered powders is reported in Table 3. These values are consistent with the standard IR peaks table [37] and clearly show the complete formation of pure phase.…”

Performance and stability of proton conducting solid oxide fuel cells based on yttrium-doped barium cerate-zirconate thin-film electrolyte

“…From these investigations, it was demonstrated that the introduction of Zr into doped barium cerate greatly enhanced its chemical stability, but the incorporation percentage of Zr required for sufficient chemical stability depended on the trivalent element doped to B site in ABO3-type perovskite of doped barium cerate zirconate for introducing oxygen ion vacancy. It was also reported that the Zr content in the range 20-40 mol% in doped barium cerate zirconate would be required to maintain high electrical conductivity and chemical stability under CO 2 -containing atmosphere [19,20]. Yttrium doped barium cerate zirconate (BaCe 1-x-y Zr x Y y O 3-, BCZY) in the form of sintered pellets has been widely investigated as one of promising proton conducting materials with high conductivity and chemical stability under CO 2 -or H 2 O-or H 2 S-containing atmosphere [20][21][22][23][24][25].…”

Characterization of cerate–zirconate ceramic powder prepared by a high-pressure–high-temperature batch-wise reactor system

“…Carbonate compound was formed due to the incomplete combustion of excessive organic matter with Ba(NO) 2 [13]. According to Robertz et al and Osman et al, high calcination temperatures ranging from 1,400 to 1,500°C are needed to decompose the carbonate traces and undesired secondary phases [12,16]. The broad absorption bands between 539 and 464 cm -1 indicate the presence of metal oxides in the samples.…”