Crystal structure and electrical conductivity of cubic fluorite-based (YO1.5) x (WO3)0.15(BiO1.5)0.85- x (0 ≤ x ≤ 0.4) solid solutions

Hsieh, Cheng Yen; Fung, Kuan‐Zong

doi:10.1007/s10008-008-0637-9

Cited by 10 publications

(4 citation statements)

References 22 publications

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“…33,34 Arora et al calculated the average segregation energy in several types of fluorite structures (CeO 2 , ZrO 2 , and UO 2 ) as a function of the dopant radii and reported that the weakest segregation tendencies appeared when using dopants with ionic radii most similar to that of the host cation. 35 However, in this study, the size mismatch between Y 3+ and Bi 3+ cations (r[Y 3+ ] = 102 pm; r[Bi 3+ ] = 117 pm), 36 is only 13%; thus, the driving force to release Y 3+ to the grain boundary is not likely to be sufficient. Moreover, the high polarizability of Bi 3+ with its lone-pair 6s 2 electrons makes it possible to accommodate the local strain fully around Y 3+ .…”

Section: Acs Applied Materials and Interfacesmentioning

confidence: 55%

“…If the difference in radius between a dopant and a host atom is large, the host atoms cannot fully cope with the strain due to the introduction of an excessive amount of dopant; thus, the dopants will more likely diffuse from the grains into the grain boundaries, which have a relatively open structure and a low strain field. , Arora et al calculated the average segregation energy in several types of fluorite structures (CeO 2 , ZrO 2 , and UO 2 ) as a function of the dopant radii and reported that the weakest segregation tendencies appeared when using dopants with ionic radii most similar to that of the host cation . However, in this study, the size mismatch between Y 3+ and Bi 3+ cations ( r [Y 3+ ] = 102 pm; r [Bi 3+ ] = 117 pm), is only 13%; thus, the driving force to release Y 3+ to the grain boundary is not likely to be sufficient. Moreover, the high polarizability of Bi 3+ with its lone-pair 6s 2 electrons makes it possible to accommodate the local strain fully around Y 3+ .…”

Section: Resultsmentioning

confidence: 99%

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Conductive Nature of Grain Boundaries in Nanocrystalline Stabilized Bi₂O₃ Thin-Film Electrolyte

Jeong

Kwak

Byeon

et al. 2018

ACS Appl. Mater. Interfaces

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Stabilized BiO has gained a considerable amount of attention as a solid electrolyte material for low-temperature solid oxide fuel cells due to its superior oxygen-ion conductivity at the temperature of relevance (≤500 °C). Despite many research efforts to measure the transport properties of stabilized BiO, the effects of grain boundaries on the electrical conductivity have rarely been reported and their results are even controversial. Here, we attempt quantitatively to assess the grain boundary contribution out of the total ionic conductivity at elevated temperatures (350-500 °C) by fabricating epitaxial and nano-polycrystalline thin films of yttrium-stabilized BiO. Surprisingly, both epitaxial and polycrystalline films show nearly identical levels of ionic conductivity, as measured by alternating current impedance spectroscopy and this is the case despite the fact that the polyfilm possesses nanosized columnar grains and thus an extremely high density of the grain boundaries. The highly conductive nature of grain boundaries in stabilized BiO is discussed in terms of the clean and chemically uniform grain boundary without segregates, and the implications for device application are suggested.

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Section: Acs Applied Materials and Interfacesmentioning

confidence: 55%

Section: Resultsmentioning

confidence: 99%

Conductive Nature of Grain Boundaries in Nanocrystalline Stabilized Bi₂O₃ Thin-Film Electrolyte

Jeong

Kwak

Byeon

et al. 2018

ACS Appl. Mater. Interfaces

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“…Additionally, these bismuth-based electrolytes show that they have high conductivity rapid start-up, but not have better stability, improved durability and higher robustness compared to zirconium-based electrolytes [19][20][21]. These studies, especially, have been concentrated on bismuthbased binary [22][23][24] and ternary type ceramic electrolytes [17,[25][26][27][28] to improve their conductivity, stability and durability. Researchers studying the binary system electrolytes have observed that nearly all of them have the stable cubic δ-Bi 2 O 3 phase and their conductivities vary from ≈10 −7 to ≈10 −2 S cm −1 [20,29].…”

Section: Introductionmentioning

confidence: 99%

Synthesizing of (Bi₂O₃)_1-x-y(Ho₂O₃)_x(Dy₂O₃)_yElectrolytes for Intermediate-Temperature Solid Oxide Fuel Cells

et al. 2016

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In present study, Ho2O3 and Dy2O3 doped Bi2O3 composite materials for intermediate-temperature solid oxide fuel cells (IT-SOFCs) were investigated. (Bi2O3)1−x−y(Ho2O3)x(Dy2O3)y ternary systems (x = 0.11, 0.13, 0.15 and y = 0.01, 0.03, 0.05, 0.07) were fabricated using conventional solid-state synthesis techniques. The samples were characterized by means of X-ray powder diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, differential thermal analysis/thermal gravimeter, and the four-point probe technique. X-ray powder diffraction measurements indicated that all samples have the stable fluorite type face centered cubic (fcc) δ-Bi2O3 phase. Scanning electron microscopy micrographs of all of the samples showed that grain size distribution was uniform. Four-point probe technique measurements showed that the conductivity of the samples increase with increase of temperature. Additionally, it has been found that the maximum conductivity values of all samples fall in a range 8.44 × 10 −2 −4.60 × 10 −1 S cm −1 and their conductivity values corresponding to the intermediatetemperature region vary in the range 1.65 × 10 −3 −2.30 × 10 −1 S cm −1. The activation energy values of the samples were calculated from log σ graphics versus 1000/T using the Arrhenius equation. It was found that there is a good agreement between the activation energy values and conductivity values.

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“…Recently, it has been known that bismuth oxide based and doped with the other two ceramic oxides are ternary materials with the properties showing promise of utility in SOFC's [1][2][3][4][5][6][7]. In addition, the need to develop oxide ion conductive materials with high conductivity and desired structure stability at low temperature directs most of the research toward solid oxide electrolyte materials.…”

Section: Introductionmentioning

confidence: 99%

Investigation of Electrical, Structural and Thermal Stability Properties of Cubic (Bi₂O₃)_1-x-y(Dy₂O₃)_x(Ho₂O₃)_y Ternary System

Kayalı¹,

Durmuş²,

Matmon³

2011

Linköping Electronic Conference Proceedings

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In the scope of this work, (Bi 2 O 3) 1-x-y (Dy 2 O 3) x (Ho 2 O 3) y ternary system (x=1,3,5,7,9,11 mol % and y=11,9,7,5,3,1 mol %, dopant concentrations) sample materials were developed using solid state reaction method sintering each of them at 650, 700, 750, 800 °C for 48 hours. Structural, electrical and thermal properties of these samples which are candidate of electrolyte for solid oxide fuel cells (SOFCs) have been evaluated by means of XRD, four-probe method, and TGA / DTA. XRD measurements showed that except the samples annealed at 650 o C, all the other samples have stabilized δ-Bi 2 O 3 phase. It was seen that duration of sintering time and temperature was rather effective on the formation of the stabilized sample materials and their other properties, such as electrical and structural properties. It was seen that the electrical conductivities of all the examples developed sintering at 700, 750 a nd 800 °C for 48 hours increases with the increasing temperature having numerical values varying in the range of 7,65x10-2 Ω.cm-1-6,11x10-1 Ω.cm-1. Activation energy of the sample A6 was calculated and it was found 0.97 eV. On the other hand, the main purpose of this study is to find an electrolyte which does not have any degradation in its properties with time; this maybe caused either interaction between the different electrochemical cell materials or by instability of the ionic conductor under operation conditions. During the heating/cooling process, the four-point probe conductivity measurements have been performed. The hysteresis curve was obtained for this sample due to time interval difference of heating/cooling processes. It was observed that there is no gradation in the structure of the sample.

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Crystal structure and electrical conductivity of cubic fluorite-based (YO1.5) x (WO3)0.15(BiO1.5)0.85- x (0 ≤ x ≤ 0.4) solid solutions

Cited by 10 publications

References 22 publications

Conductive Nature of Grain Boundaries in Nanocrystalline Stabilized Bi₂O₃ Thin-Film Electrolyte

Conductive Nature of Grain Boundaries in Nanocrystalline Stabilized Bi₂O₃ Thin-Film Electrolyte

Synthesizing of (Bi₂O₃)_1-x-y(Ho₂O₃)_x(Dy₂O₃)_yElectrolytes for Intermediate-Temperature Solid Oxide Fuel Cells

Investigation of Electrical, Structural and Thermal Stability Properties of Cubic (Bi₂O₃)_1-x-y(Dy₂O₃)_x(Ho₂O₃)_y Ternary System

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Crystal structure and electrical conductivity of cubic fluorite-based (YO1.5) x (WO3)0.15(BiO1.5)0.85- x (0 ≤ x ≤ 0.4) solid solutions

Cited by 10 publications

References 22 publications

Conductive Nature of Grain Boundaries in Nanocrystalline Stabilized Bi2O3 Thin-Film Electrolyte

Conductive Nature of Grain Boundaries in Nanocrystalline Stabilized Bi2O3 Thin-Film Electrolyte

Synthesizing of (Bi2O3)1-x-y(Ho2O3)x(Dy2O3)yElectrolytes for Intermediate-Temperature Solid Oxide Fuel Cells

Investigation of Electrical, Structural and Thermal Stability Properties of Cubic (Bi2O3)1-x-y(Dy2O3)x(Ho2O3)y Ternary System

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Conductive Nature of Grain Boundaries in Nanocrystalline Stabilized Bi₂O₃ Thin-Film Electrolyte

Conductive Nature of Grain Boundaries in Nanocrystalline Stabilized Bi₂O₃ Thin-Film Electrolyte

Synthesizing of (Bi₂O₃)_1-x-y(Ho₂O₃)_x(Dy₂O₃)_yElectrolytes for Intermediate-Temperature Solid Oxide Fuel Cells

Investigation of Electrical, Structural and Thermal Stability Properties of Cubic (Bi₂O₃)_1-x-y(Dy₂O₃)_x(Ho₂O₃)_y Ternary System