resumo
The influence of phosphorous additions on the sintering and electrical transport properties of the proton-conducting perovskite BaZr0.85Y0.15O3-delta (BZY) has been studied with a view to the use of phosphates as typical dispersants for the formation of stabilised solid suspensions or as possible sintering aids. P2O5 additions, (1-x)BZY.xP(2)O(5), monotonously promote densification in the intermediate compositional range 0.04 <= x <= 0.08. Nonetheless, BZY reacts with phosphorous forming the phase Ba-3(PO4)(2) at temperatures as low as 600 degrees C. The associated loss of Ba from the perovskite, leads to a decrease in the perovskite lattice parameter, the formation of yttria-based impurity phases and impaired grain growth. Such reaction has an extremely detrimental effect on bulk and grain boundary conductivities. It is, therefore, vital that the current results are taken into account by the protonics community when attempting to prepare the stabilised solid suspensions of BZY nanopowders required for thin ceramic applications. Alternative dispersants to phosphate esters must be found. (C) 2012 Elsevier Inc. All rights reserved.
palavras-chave
DOPED BARIUM ZIRCONATE; OXIDE FUEL-CELLS; PHOSPHATE ESTER; THIN-FILMS; BATIO3; ELECTROLYTE; MICROSTRUCTURE; DISPERSION; CERAMICS; TITANATE
categoria
Chemistry
autores
Soares, HS; Zhang, X; Antunes, I; Frade, JR; Mather, GC; Fagg, DP
nossos autores
Isabel Alexandra Gonçalves Antunes
Investigador Júnior
Jorge Ribeiro Frade
Professor(a) Jubilado(a)agradecimentos
The authors acknowledge financial support from the FCT, Portugal (Grants PTDC/CTM/64357/2006, SFRH/BD/60265/2009, PTDC/CTM/105424/2008, PTDC/CTM/100412/2008) and the MICINN, Spain (ENE2009-14750-C05-03).