Effects of A- and B-site (co-)acceptor doping on the structure and proton conductivity of LaNbO4

Publication: Research - peer-reviewConference article – Annual report year: 2011

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Effects of A- and B-site (co-)acceptor doping on the structure and proton conductivity of LaNbO4. / Ivanova, M.; Ricote, Sandrine; Meulenberg, W.A.; Haugsrud, R.; Ziegner, M.

In: Solid State Ionics, Vol. 213, 2012, p. 45-52.

Publication: Research - peer-reviewConference article – Annual report year: 2011

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Ivanova, M.; Ricote, Sandrine; Meulenberg, W.A.; Haugsrud, R.; Ziegner, M. / Effects of A- and B-site (co-)acceptor doping on the structure and proton conductivity of LaNbO4.

In: Solid State Ionics, Vol. 213, 2012, p. 45-52.

Publication: Research - peer-reviewConference article – Annual report year: 2011

Bibtex

@article{a811bc7e6568421c8eff2242cdfff80b,
title = "Effects of A- and B-site (co-)acceptor doping on the structure and proton conductivity of LaNbO4",
publisher = "Elsevier BV North-Holland",
author = "M. Ivanova and Sandrine Ricote and W.A. Meulenberg and R. Haugsrud and M. Ziegner",
year = "2012",
doi = "10.1016/j.ssi.2011.06.012",
volume = "213",
pages = "45--52",
journal = "Solid State Ionics",
issn = "0167-2738",

}

RIS

TY - CONF

T1 - Effects of A- and B-site (co-)acceptor doping on the structure and proton conductivity of LaNbO4

A1 - Ivanova,M.

A1 - Ricote,Sandrine

A1 - Meulenberg,W.A.

A1 - Haugsrud,R.

A1 - Ziegner,M.

AU - Ivanova,M.

AU - Ricote,Sandrine

AU - Meulenberg,W.A.

AU - Haugsrud,R.

AU - Ziegner,M.

PB - Elsevier BV North-Holland

PY - 2012

Y1 - 2012

N2 - B-site and A- and B-site co-doped lanthanum niobates, La(1-x)DA(x)Nb(1-y)DB(y)O(4-δ), where DA stands for Ca or Ba and DB for Ga, Ge or In (x = 0 or 0.01; y = 0.01), have been synthesized via the solid-state route. Essentially single-phase materials were obtained after 10 h at 1500 °C with monoclinic Fergusonite structure at room temperature. The unit cell volume increases slightly with the presence of the acceptor. The electrical conductivity of the materials, characterized as a function of the temperature from 300 °C to 900 °C under wet reducing conditions with AC impedance spectroscopy, was dominated by protons. The maximum conductivity of 4.1 · 10−4 S · cm−1 at 900 °C was obtained for La0.99Ca0.01Nb0.99Ga0.01O4-δ, which is a factor of ~ 2.5 lower than the highest conductivity reported for the A-site Ca-doped LaNbO4. Based on a semi-quantitative evaluation it was shown that the hydration of the B-site and A- and B-site co-doped LaNbO4 is slightly more exothermic and that the proton mobility has higher activation enthalpies than Ca-doped LaNbO4. This is accounted for by a stronger association between the acceptor and the proton for B-site than for A-site doping.

AB - B-site and A- and B-site co-doped lanthanum niobates, La(1-x)DA(x)Nb(1-y)DB(y)O(4-δ), where DA stands for Ca or Ba and DB for Ga, Ge or In (x = 0 or 0.01; y = 0.01), have been synthesized via the solid-state route. Essentially single-phase materials were obtained after 10 h at 1500 °C with monoclinic Fergusonite structure at room temperature. The unit cell volume increases slightly with the presence of the acceptor. The electrical conductivity of the materials, characterized as a function of the temperature from 300 °C to 900 °C under wet reducing conditions with AC impedance spectroscopy, was dominated by protons. The maximum conductivity of 4.1 · 10−4 S · cm−1 at 900 °C was obtained for La0.99Ca0.01Nb0.99Ga0.01O4-δ, which is a factor of ~ 2.5 lower than the highest conductivity reported for the A-site Ca-doped LaNbO4. Based on a semi-quantitative evaluation it was shown that the hydration of the B-site and A- and B-site co-doped LaNbO4 is slightly more exothermic and that the proton mobility has higher activation enthalpies than Ca-doped LaNbO4. This is accounted for by a stronger association between the acceptor and the proton for B-site than for A-site doping.

KW - Proton-conducting ceramic materials

KW - Rare earth ortho-niobates

KW - Acceptor-doped lanthanum niobate

U2 - 10.1016/j.ssi.2011.06.012

DO - 10.1016/j.ssi.2011.06.012

JO - Solid State Ionics

JF - Solid State Ionics

SN - 0167-2738

VL - 213

SP - 45

EP - 52

ER -