Mechanosynthesis of nanopowders of the proton-conducting electrolyte material Ba(Zr, Y)O3-delta

authors	Antunes, I; Brandao, A; Figueiredo, FM; Frade, JR; Gracio, J; Fagg, DP
nationality	International
journal	JOURNAL OF SOLID STATE CHEMISTRY
author keywords	Barium zirconate; BaZrO3; Mechanosynthesis; Nanopowders; Perovskite; Proton conductor
keywords	LOW-TEMPERATURE SYNTHESIS; DOPED BARIUM ZIRCONATE; SPRAY-PYROLYSIS; BAZRO3; TRANSPORT; ROUTE; OXIDE
abstract	The formation of perovskite nanopowders of the common proton-conducting, electrolyte material Ba(Zr1-xYx)O3-delta is demonstrated by room temperature mechanosynthesis for the compositional range x = 0, 0.058 and 0.148. This is achieved with a planetary ball mill at 650 rpm in zirconia vials, starting from BaO2 with ZrO2, (ZrO2)0.97(Y2O3)(0.03) or (ZrO2)(0.92)(Y2O3)(0.08) precursors, respectively. Powder X-ray diffraction (XRD) reveals the formation of the perovskite phase in the early stages of milling with phase purity being achieved after milling times of 240 min for composition x = 0.058 whereas 420 min is necessary for composition x = 0.148. In contrast, traces of ZrO2 are apparent in composition x = 0 even after milling times of 420 min. The use of BaCO3 as precursor does not allow the formation of the perovskite phase for any composition. The perovskite crystallites are spherical in shape with an average size determined from XRD of ca. 30 nm in agreement with transmission electron microscopy observations. FTIR spectra demonstrate that contamination levels of BaCO3 in the mechanosynthesized powders are very low, The spherical shape and nanoscale of the crystallites allow densification levels that are highly competitive when compared to BaZrO3-based materials formed by alternative synthesis techniques documented in the literature. (C) 2009 Elsevier Inc. All rights reserved.
publisher	ACADEMIC PRESS INC ELSEVIER SCIENCE
issn	0022-4596
year published	2009
volume	182
issue	8
beginning page	2149
ending page	2156
digital object identifier (doi)	10.1016/j.jssc.2009.05.027
web of science category	Chemistry, Inorganic & Nuclear; Chemistry, Physical
subject category	Chemistry
unique article identifier	WOS:000269066400024