Effect of phosphorus additions on the sintering and transport properties of proton conducting BaZr{sub 0.85}Y{sub 0.15}O{sub 3-{delta}}

Journal Article · Sun Jul 15 04:00:00 EDT 2012 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/J.JSSC.2012.02.053· OSTI ID:22012167

Soares, H S ^[1]; Zhang, X ^[2]; Antunes, I ^[1]; Frade, J R ^[2]; Mather, G C ^[3]

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1. Nanotechnology Research Division, TEMA, Department of Mechanical Engineering, University of Aveiro, 3810-193 Aveiro (Portugal)
2. Department of Ceramic and Glass Engineering, CICECO, University of Aveiro, 3810-193 Aveiro (Portugal)
3. Institute of Ceramics and Glass, CSIC, 28049 Madrid (Spain)

The influence of phosphorous additions on the sintering and electrical transport properties of the proton-conducting perovskite BaZr{sub 0.85}Y{sub 0.15}O{sub 3-{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. P{sub 2}O{sub 5} additions, (1-x)BZY{center_dot}xP{sub 2}O{sub 5}, monotonously promote densification in the intermediate compositional range 0.04{<=}x{<=}0.08. Nonetheless, BZY reacts with phosphorous forming the phase Ba{sub 3}(PO{sub 4}){sub 2} at temperatures as low as 600 Degree-Sign 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. - Graphical Abstract: Sintering experiments performed at 1500 Degree-Sign C for 5 h and at 1400 Degree-Sign C for 24 h of (1-x)BaZr{sub 0.85}Y{sub 0.15}O{sub 3-{delta}}{center_dot}xP{sub 2}O{sub 5} in the range x=0-0.10. Highlights: Black-Right-Pointing-Pointer P{sub 2}O{sub 5} additions, (1-x)BZY{center_dot}xP{sub 2}O{sub 5}, promote densification in the intermediate compositional range 0.04{<=}x{<=}0.08. Black-Right-Pointing-Pointer BZY reacts with phosphorous forming the phase Ba{sub 3}(PO{sub 4}){sub 2} at temperatures as low as 600 Degree-Sign C. Black-Right-Pointing-Pointer Detrimental effects on bulk and grain boundary conductivities are shown. Black-Right-Pointing-Pointer Alternative dispersants to phosphate esters must be found.

• OSTI ID: 22012167
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Vol. . 191; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM PHOSPHATES
CERAMICS
ESTERS
GRAIN BOUNDARIES
GRAIN GROWTH
IMPURITIES
LATTICE PARAMETERS
NANOSTRUCTURES
PEROVSKITE
PHOSPHORUS ADDITIONS
PHOSPHORUS OXIDES
POWDERS
PROTONS
SINTERING
SOLIDS
SUSPENSIONS
YTTRIUM OXIDES
ZIRCONATES