The effects of dopants and A:B site nonstoichiometry on properties of perovskite-type proton conductors

Journal Article · Fri May 01 04:00:00 EDT 1998 · Journal of the Electrochemical Society

DOI:https://doi.org/10.1149/1.1838557· OSTI ID:653267

Guan, J ^[1]; Dorris, S E; Balachandran, U ^[1]; Liu, M ^[2]

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1. Argonne National Lab., IL (United States). Energy Technology Div.
2. Georgia Inst. of Tech., Atlanta, GA (United States). School of Materials Science and Engineering

Investigations of perovskite-type BaCeO{sub 3} and SrCeO{sub 3} with various dopants (Y, Gd, Nd, and Ni) indicate that their microstructures and electrical properties are strongly influenced by the type and amount of dopants. Grain growth and densification of sintered samples are influenced by dopant level and A:B site nonstoichiometry. The conductivity of BaCe{sub 1{minus}x}Y{sub x}O{sub 3{minus}{delta}} increases with the yttrium content in hydrogen and wet Ar, and exhibits a maximum in oxygen at a yttrium content of 10 to 20%. BaCe{sub 0.8}Y{sub 0.2}O{sub 3{minus}{delta}} has the highest conductivity in a hydrogen atmosphere: {approximately} 1.54 {times} 10{sup {minus}2} {Omega}{sup {minus}1} cm{sup {minus}1} at 600 C, and {approximately} 4.16 {times} 10{sup {minus}2} {Omega}{sup {minus}1} cm{sup {minus}1} at 800 C. The effect of BaO excess depends on the concentration of dopant. Compared with BaCe{sub 0.95}Y{sub 0.05}O{sub 3{minus}{delta}}, doped BaCeO{sub 3} with BaO excess (BaO{center_dot}0.90CeO{sub 2}{center_dot}0.025Y{sub 2}O{sub 3}) has a higher total conductivity in all atmospheres studied (O{sub 2}, H{sub 2}, and wet Ar), whereas the conductivity of BaCeO{sub 3} with excess BaO (BaO{center_dot}0.85CeO{sub 2}{center_dot}0.05Y{sub 2}O{sub 3}) is lower than that of BaCe{sub 0.9}Y{sub 0.1}O{sub 3{minus}{delta}}. BaCeO{sub 3} based materials have higher conductivities than those of SrCeO{sub 3} based materials, whereas SrCeO{sub 3} based materials show higher proton transference numbers.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 653267
• Journal Information: Journal of the Electrochemical Society, Journal Name: Journal of the Electrochemical Society Journal Issue: 5 Vol. 145; ISSN JESOAN; ISSN 0013-4651
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM OXIDES
CERIUM OXIDES
DOPED MATERIALS
ELECTRICAL PROPERTIES
EXPERIMENTAL DATA
GADOLINIUM
METALLURGICAL EFFECTS
MICROSTRUCTURE
NEODYMIUM
NICKEL
STRONTIUM OXIDES
YTTRIUM