Structural and electrical consequences of high dopant levels in the BIMGVOX system

Krok, F.; Abrahams, Isaac; Małys, M.; Bogusz, W.; Dygas, J.R.; Nelstrop, J.A.G; Bush, Alexandra

doi:10.1016/s0167-2738(00)00360-x

Cited by 36 publications

(11 citation statements)

References 9 publications

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“…The cell remains orthorhombic within all the composition range but the α→β change occurs with characteristic increase in c-parameter [13,14] with the a and b axes remaining fairly constant and are very much dependant on the dopant. Above x=0.2, there is a drop in volume due to variation in a, b and c axes, which indicates that a value of x=0.2 is the limit of solid solution range [15].…”

Section: X-ray Diffractionmentioning

confidence: 99%

Structural, thermal and transport properties of $$ {\text{B}}{{\text{i}}_4}{{\text{V}}_{2 - {\text{x}}}}{\text{G}}{{\text{a}}_{\text{x}}}{{\text{O}}_{11 - \delta }} $$ (0 ≤ x ≤ 0.4)

Kant

Singh

Pandey

2009

Ionics

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Solid electrolytes are mostly used in solid oxide fuel cells (SOFC). In the present study, gallium-substituted compounds (Bi 4 V 2Àx Me x O 11Àd ; Me=Ga 3+ ; 0≤x≤0.4) were prepared by solid-state reaction technique for its use as an electrolyte in SOFC. Structural and conductivity behavior was studied as a function of the Ga 3+ substitution on vanadium site. The compounds remain in the orthorhombic α-phase for x=0 and 0.1 whereas higher concentration of dopant leads to β-phase stabilization. The highest and lowest ionic conductivity were observed in x=0.2 and x=0.4 samples, respectively. The prepared samples were studied by using alternating current conductivity, differential thermal analysis and X-ray diffraction techniques. The results are discussed on the basis of formation of oxygen vacancy and its ordering.

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Section: X-ray Diffractionmentioning

confidence: 99%

Structural, thermal and transport properties of $$ {\text{B}}{{\text{i}}_4}{{\text{V}}_{2 - {\text{x}}}}{\text{G}}{{\text{a}}_{\text{x}}}{{\text{O}}_{11 - \delta }} $$ (0 ≤ x ≤ 0.4)

Kant

Singh

Pandey

2009

Ionics

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“…1) were obtained. In all the obtained patterns, the peak ~ 32 ⁰ was found to be singlet which is the characteristic of γ -phase, hence all of the samples were attributed to γ -symmetry [8]. The increase in value of 'c' parameter is observed in case of Ba 2+ and Sr 2+ doped samples than in undoped sample all the lattice parameter values are listed in table 2 [9].…”

Section: X-ray Diffraction Analysismentioning

confidence: 81%

Structural and optical study of γ –BIMEVOX; ME: Ba2+ and Sr2+

Gupta¹,

Singh²

2015

AIP Conference Proceedings

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Bismuth oxide based compounds, such as Bi 4 V 2 O 11-δ (BIVOX) , exhibit Aurivillus type of interleaving arrangement of (Bi 2 O 2 ) 2+ and (VO 3 □ 0.5 ) 2-(□: oxygen vacancies). Bi 4 V 2 O 11-δ, is known to have three kinds of temperature dependent interconvertible polymorphs α (monoclinic), β (orthorhombic) and γ (tetragonal). Out of all the three phases, the γ -phase is highly disordered and hence, is the most conductive one which can be stabilized by proper lower valence cation (ME) doping at V site. Bi 4 V 1.90 ME 0.20 O 11-δ (ME: Ba 2+ and Sr 2+ ) were prepared via splat quenching technique. The required compositions were melted at 1250 C in an electric furnace. The as quenched samples were sintered at 800 C for 12 hours (h). The formed phases were analyzed using X-ray diffraction on quenched and sintered samples, the peak at 32 is found to be singlet in all the samples which confirms the presence of γ-phase. Hence, the stabilization of γ-phase with tetragonal structure was found to have taken place with doping and quenching. These samples are also studied by FT-IR and UV/vis spectroscopy to investigate the effect of dopants on structure and band gaps respectively.

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“…Few reports have been appeared in the literature to synthesize Bi 4 V 2 O 11 À δ by melt quench followed by sintering [10,11]. The objective of the present study is to investigate the effect of melt quench followed by sintering technique on γ-phase stabilization, phase transitions and conductivity with respect to temperature.…”

Section: Introductionmentioning

confidence: 97%

“…Kant et al [9] studied the effect of sintering temperature on the conductivity of Bi 4 V 2 À x Ti x O 11 À δ system and reported that increasing the sintering temperature above 800 1C decreases the overall conductivity of the system. Krok et al [10] reported that number of oxygen vacancies is more in case of quenched samples than in slow cooled samples. As quenching from high temperature to room temperature prevents the re-oxidation of vanadium and stabilizes the high temperature disordered γ-Bi 4 V 2 O 11 À δ at room temperature.…”

Section: Introductionmentioning

confidence: 99%

“…The objective of the present study is to investigate the effect of melt quench followed by sintering technique on γ-phase stabilization, phase transitions and conductivity with respect to temperature. It is expected that the melt quench will not only increase the solid solubility limit of dopant but also easily stabilize the γ-phase at room temperature [9][10][11][12]. Thus, based on the above observations, Bi 4 V 2 À x ME x O 11 À δ (ME: Mg 2 þ , Ca 2 þ ) have been synthesized via the melt quench technique to study the effect of processing conditions on phase stabilization, density and conductivity of the system.…”

Section: Introductionmentioning

confidence: 99%

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Effect of two different dopants (Mg2+ and Ca2+) and processing parameters on γ-phase stabilization and conductivity of Bi4V2O11−δ

Gupta

Singh

2015

Ceramics International

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Structural and electrical consequences of high dopant levels in the BIMGVOX system

Cited by 36 publications

References 9 publications

Structural, thermal and transport properties of $$ {\text{B}}{{\text{i}}_4}{{\text{V}}_{2 - {\text{x}}}}{\text{G}}{{\text{a}}_{\text{x}}}{{\text{O}}_{11 - \delta }} $$ (0 ≤ x ≤ 0.4)

Structural, thermal and transport properties of $$ {\text{B}}{{\text{i}}_4}{{\text{V}}_{2 - {\text{x}}}}{\text{G}}{{\text{a}}_{\text{x}}}{{\text{O}}_{11 - \delta }} $$ (0 ≤ x ≤ 0.4)

Structural and optical study of γ –BIMEVOX; ME: Ba2+ and Sr2+

Effect of two different dopants (Mg2+ and Ca2+) and processing parameters on γ-phase stabilization and conductivity of Bi4V2O11−δ

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