Synthesis, rietveld refinement of crystal structure, electron diffraction, and electrical transport properties of Ba2(Ca1- x - YFe x Nb y)(Nb1- zFe z)O 6-δ double perovskites

Wang Hay Kan; Trang T. Trinh; Tobias Fürstenhaupt; Venkataraman Thangadurai

doi:10.1139/v11-058

Synthesis, rietveld refinement of crystal structure, electron diffraction, and electrical transport properties of Ba₂(Ca_{1- x - Y}Fe _x Nb _y)(Nb_{1- z}Fe _z)O _6-δ double perovskites

Wang Hay Kan, Trang T. Trinh, Tobias Fürstenhaupt, Venkataraman Thangadurai^*

^*Corresponding author for this work

School of Chemistry

Research output: Contribution to journal › Article › peer-review

Abstract

We report the synthesis, crystal structure, and electrochemical properties of new Fe-doped Ba₂(Ca_1-x-yFe_xNb _y)(Nb_1-zFe_z)O_6-δ (Fe-BCN). The Fe-BCN was synthesized by a solid-state method in air using corresponding metal oxides and salts at elevated temperature. All of the observed powder X-ray diffraction (PXRD) peaks of the investigated Fe-BCN were indexed as cubic Fm-3m (space group No. 225) double perovskite-type structure with cell constants a ∼ 8.4 Å and is consistent with selected area electron diffraction (SAED). Rietveld analysis suggested the distribution of Fe was at both 4a and 4b sites, supported the proposed chemical formula Ba₂(Ca _1-x-yFe_xNb_y)(Nb_1-zFe _z)O_6-δ. This was further verified by bond valence sum (BVS) analysis of the cations. The Fe-BCN showed superior chemical stability in pure CO₂ and boiling H₂O confirmed by PXRD and FTIR. The electrical conductivity was determined by AC impedance spectroscopy. Among the samples investigated, Ba₂(Ca_0.79Fe_0.21) (Nb_0.71Fe_0.29)O_6-δ showed the highest total (bulk + grain-boundary) conductivity of 1.1 × 10^-2 S cm^-1 in humidified (3%) N₂ at 600 °C with activation energy of 0.43 eV in the temperature range 200-800 °C.

Original language	English
Pages (from-to)	688-696
Number of pages	9
Journal	Canadian Journal of Chemistry
Volume	89
Issue number	6
DOIs	https://doi.org/10.1139/v11-058
Publication status	Published - Jun 2011

Keywords

AC impedance spectroscopy
anodes
Fe-BCNs
mixed ionic and electronic conductors (MIECs)
perovskites
Powder X-ray diffraction (PXRD)
Protonic conductors
Rietveld refinement
Selected area electron diffraction (SAED)
solid oxide fuel cells (SOFCs)

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10.1139/v11-058

Cite this

@article{1bdecc2f4fec44d5897807330b50247d,

title = "Synthesis, rietveld refinement of crystal structure, electron diffraction, and electrical transport properties of Ba2(Ca1- x - YFe x Nb y)(Nb1- zFe z)O 6-δ double perovskites",

abstract = "We report the synthesis, crystal structure, and electrochemical properties of new Fe-doped Ba2(Ca1-x-yFexNb y)(Nb1-zFez)O6-δ (Fe-BCN). The Fe-BCN was synthesized by a solid-state method in air using corresponding metal oxides and salts at elevated temperature. All of the observed powder X-ray diffraction (PXRD) peaks of the investigated Fe-BCN were indexed as cubic Fm-3m (space group No. 225) double perovskite-type structure with cell constants a ∼ 8.4 {\AA} and is consistent with selected area electron diffraction (SAED). Rietveld analysis suggested the distribution of Fe was at both 4a and 4b sites, supported the proposed chemical formula Ba2(Ca 1-x-yFexNby)(Nb1-zFe z)O6-δ. This was further verified by bond valence sum (BVS) analysis of the cations. The Fe-BCN showed superior chemical stability in pure CO2 and boiling H2O confirmed by PXRD and FTIR. The electrical conductivity was determined by AC impedance spectroscopy. Among the samples investigated, Ba2(Ca0.79Fe0.21) (Nb0.71Fe0.29)O6-δ showed the highest total (bulk + grain-boundary) conductivity of 1.1 × 10-2 S cm-1 in humidified (3%) N2 at 600 °C with activation energy of 0.43 eV in the temperature range 200-800 °C.",

keywords = "AC impedance spectroscopy, anodes, Fe-BCNs, mixed ionic and electronic conductors (MIECs), perovskites, Powder X-ray diffraction (PXRD), Protonic conductors, Rietveld refinement, Selected area electron diffraction (SAED), solid oxide fuel cells (SOFCs)",

author = "Kan, {Wang Hay} and Trinh, {Trang T.} and Tobias F{\"u}rstenhaupt and Venkataraman Thangadurai",

year = "2011",

month = jun,

doi = "10.1139/v11-058",

language = "English",

volume = "89",

pages = "688--696",

journal = "Canadian Journal of Chemistry",

issn = "0008-4042",

publisher = "National Research Council of Canada",

number = "6",

}

Synthesis, rietveld refinement of crystal structure, electron diffraction, and electrical transport properties of Ba₂(Ca_{1- x - Y}Fe _x Nb _y)(Nb_{1- z}Fe _z)O _6-δ double perovskites. / Kan, Wang Hay; Trinh, Trang T.; Fürstenhaupt, Tobias et al.
In: Canadian Journal of Chemistry, Vol. 89, No. 6, 06.2011, p. 688-696.

Research output: Contribution to journal › Article › peer-review

TY - JOUR

T1 - Synthesis, rietveld refinement of crystal structure, electron diffraction, and electrical transport properties of Ba2(Ca1- x - YFe x Nb y)(Nb1- zFe z)O 6-δ double perovskites

AU - Kan, Wang Hay

AU - Trinh, Trang T.

AU - Fürstenhaupt, Tobias

AU - Thangadurai, Venkataraman

PY - 2011/6

Y1 - 2011/6

N2 - We report the synthesis, crystal structure, and electrochemical properties of new Fe-doped Ba2(Ca1-x-yFexNb y)(Nb1-zFez)O6-δ (Fe-BCN). The Fe-BCN was synthesized by a solid-state method in air using corresponding metal oxides and salts at elevated temperature. All of the observed powder X-ray diffraction (PXRD) peaks of the investigated Fe-BCN were indexed as cubic Fm-3m (space group No. 225) double perovskite-type structure with cell constants a ∼ 8.4 Å and is consistent with selected area electron diffraction (SAED). Rietveld analysis suggested the distribution of Fe was at both 4a and 4b sites, supported the proposed chemical formula Ba2(Ca 1-x-yFexNby)(Nb1-zFe z)O6-δ. This was further verified by bond valence sum (BVS) analysis of the cations. The Fe-BCN showed superior chemical stability in pure CO2 and boiling H2O confirmed by PXRD and FTIR. The electrical conductivity was determined by AC impedance spectroscopy. Among the samples investigated, Ba2(Ca0.79Fe0.21) (Nb0.71Fe0.29)O6-δ showed the highest total (bulk + grain-boundary) conductivity of 1.1 × 10-2 S cm-1 in humidified (3%) N2 at 600 °C with activation energy of 0.43 eV in the temperature range 200-800 °C.

AB - We report the synthesis, crystal structure, and electrochemical properties of new Fe-doped Ba2(Ca1-x-yFexNb y)(Nb1-zFez)O6-δ (Fe-BCN). The Fe-BCN was synthesized by a solid-state method in air using corresponding metal oxides and salts at elevated temperature. All of the observed powder X-ray diffraction (PXRD) peaks of the investigated Fe-BCN were indexed as cubic Fm-3m (space group No. 225) double perovskite-type structure with cell constants a ∼ 8.4 Å and is consistent with selected area electron diffraction (SAED). Rietveld analysis suggested the distribution of Fe was at both 4a and 4b sites, supported the proposed chemical formula Ba2(Ca 1-x-yFexNby)(Nb1-zFe z)O6-δ. This was further verified by bond valence sum (BVS) analysis of the cations. The Fe-BCN showed superior chemical stability in pure CO2 and boiling H2O confirmed by PXRD and FTIR. The electrical conductivity was determined by AC impedance spectroscopy. Among the samples investigated, Ba2(Ca0.79Fe0.21) (Nb0.71Fe0.29)O6-δ showed the highest total (bulk + grain-boundary) conductivity of 1.1 × 10-2 S cm-1 in humidified (3%) N2 at 600 °C with activation energy of 0.43 eV in the temperature range 200-800 °C.

KW - AC impedance spectroscopy

KW - anodes

KW - Fe-BCNs

KW - mixed ionic and electronic conductors (MIECs)

KW - perovskites

KW - Powder X-ray diffraction (PXRD)

KW - Protonic conductors

KW - Rietveld refinement

KW - Selected area electron diffraction (SAED)

KW - solid oxide fuel cells (SOFCs)

U2 - 10.1139/v11-058

DO - 10.1139/v11-058

M3 - Article

AN - SCOPUS:80051488628

SN - 0008-4042

VL - 89

SP - 688

EP - 696

JO - Canadian Journal of Chemistry

JF - Canadian Journal of Chemistry

IS - 6