The influence of grain structures on the electrical conductivity of a BaZr0.95Y0.05O3 proton conductor

Processing of yttrium-doped barium zirconate for high proton conductivity

“…Specifically, barium deficiency was shown to lower the conductivity by 2 orders of magnitude, and it is believed that stoichiometric differences induced by severe processing conditions are the major contributor to the wide variation in literature data for the conductivity of BYZ. Indeed, the recent observation of Iguchi et al 15 that prolonged sintering at 1800°C lowers the conductivity of BaZr 0.95 y 0.05 O 3−x by three orders of magnitude may also be attributable to barium loss.…”

Preparation and proton conductivity of ultrafine Y-doped BaZrO₃ ceramics

“…On the contrary, high density ceramics can be sintered from sand milled powders at 1640°C for 15 h. Most notably, the sintered compact from the powders that were sand-milled for 5 h achieve almost their full density (99%), which is slightly higher than that prepared by Pechini method (almost 98% sintered at 1800°C for 20 h). 21), 22) These results indicate that sand milling at high rotation speed can efficiently eliminate the aggregation of calcined powders and greatly improve the sintering activity of powders.…”

“…This microstructure is similar to that prepared by Pechini method which is economically unfavorable for industrial application for expensive precursors and complicated procedures. 21) Consequently, as the particle size of as-synthesized powder diminishes rapidly when pulverized by sand-milling, the sintering is significantly improved leading to highly densified pellets without requiring high sintering temperatures. Typically after sand-milling for 5 h, the aggregated powder is ground into very small and well-dispersed particles (d500.127¯m), hence enhancing grain growth and achieving a relative density of 99%, with uniform and ultrafine grains produced by sintering at 1640°C for 15 h. BZY powders prepared by the solid-state reaction method are usually hard to sinter even when using very high temperatures.…”

Efeito da adição de óxido de zinco e de óxido de boro nas propriedades do zirconato de bário dopado com ítrio

“…Uma solução foi proposta para a gradual substituição do Zr 4+ por Ce 4+ no zirconato de bário [30][31][32]. Uma forma importante de melhorar as propriedades elétricas do zirconato de bário seria a redução da resistividade elétrica do contorno de grão [33].…”