Temperature and frequency dependence of transport phenomena in co-doped rare earth oxides nanoparticles for ITSOFCs

Abdullah, A.; Saleemi, Awais Siddique; Anis-ur-Rehman, M.

doi:10.1016/j.jallcom.2015.01.236

Cited by 13 publications

(5 citation statements)

References 24 publications

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“…In this way, the increase in content of 3+ ions in the structure of CeO 2 generates an growth in electrical transport and decreases the resistance . Similarly Pr 3+ ions generate high carrier mobility (

V_{o}^{∙ ∙}

), which induce an electric transport on the grain boundaries by a jump mechanism, causing a balance between electron and ion conduction . The capacitance value for X = 0.8 is higher than X = 0.6, which indicates that the material accumulates high charge levels and predicts the increase of charge mobility at high temperatures, since the resistance of the material is related to the frequency of relaxation of the maximum point of the impedance plot semicircle, and this relationship is maintained at different temperature ranges.…”

Section: Resultsmentioning

confidence: 99%

Effect of Pr on the electrical and chemical properties of cerium oxide prepared by combustion method

Cruz-Pacheco

Cuaspud

Vargas

et al. 2019

Int J Applied Ceramic Tech

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Nanoparticles of Ce 1−x Pr x O 2 (X: 0.6 and 0.8), were synthesized by the combustion method using citric acid as chelating and fuel agent. The X-ray diffraction patterns and Rietveld refinements confirm that samples shown as a single phase in a cubic fluorite structure, with an increase in the lattice parameter as a function of Pr concentration. The crystallite size domains obtained by the Scherrer formula, confirm values around 10 and 37 nm. The scanning electron microscopy images, show that the solids are composed of dense heterogeneous aggregates. The X-ray photoelectron spectroscopy, reveals that oxides are composed of cerium and praseodymium cations in oxidation states 4+ and 3+ respectively. The TPR-H 2 profiles indicate that cerium and praseodymium cations present in the obtained systems are completely reduced to Ce 3+ and Pr 3+ at temperatures above 790°C. The impedance spectroscopy data at room temperature showed that the conduction processes for the two systems take place at the grain boundaries. The Ce 0.2 Pr 0.8 O 2 system offer lower resistance, due to the high amount of Pr 3+ ions inserted in the structure and the high amount of oxygen vacancies formed in the synthesis process.

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V_{o}^{∙ ∙}

Section: Resultsmentioning

confidence: 99%

Effect of Pr on the electrical and chemical properties of cerium oxide prepared by combustion method

Cruz-Pacheco

Cuaspud

Vargas

et al. 2019

Int J Applied Ceramic Tech

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show abstract

“…Molar ratio (0.515:0.485) was used for the NaOH-KOH as a reactant and precipitating process. Eutectic point of this system was 170°C [30][31][32][33]. Firstly, precursors were well ground, mixed and put in a Teflon container.…”

Section: Methodsmentioning

confidence: 99%

“…Firstly, precursors were well ground, mixed and put in a Teflon container. Later it was placed in a pre-heated oven set at a temperature of 180°C for a time limit of 65 min [30,31,33]. After 65 min, the oven was switched off and allowed to cool at room temperature.…”

Section: Methodsmentioning

confidence: 99%

“…In the literature, different routes have been adopted so far to synthesize BSCF cathode material such as solid-state reaction route [13,14,[21][22][23], EDTA complexing method [22,24,25] etc. Beside these synthesis methods, wet chemical methods have good control on complex composition synthesis and good chemical homogeneity of the final product [26][27][28][29][30][31]. Therefore, in this work modified and easy to handle wet chemical synthesis techniques were designed to synthesize BSCF as promising IT-SOFCs cathode material.…”

Section: Introductionmentioning

confidence: 99%

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Reduced impedance in dual substituted strontium cobaltite nanoparticles for renewable energy applications

Akhtar

Anis-ur-Rehman

2020

Mater. Res. Express

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Sr 1−x Ba x Co 1−x Fe x O 3−δ (BSCF) nanoparticles were successfully synthesized with three modified wet chemical techniques; composite mediated hydrothermal method (CMHM), without water and surfactants (WOWS) sol-gel and co-precipitation methods. The probable electrical conduction mechanism of synthesized BSCF was explored via complex impedance analysis. Various physicochemical characterization techniques were employed to study the dependence of structure, homogeneity, physical parameters and electrical properties of BSCF on synthesis procedures. X-ray Diffraction (XRD) confirmed the formation of cubic BSCF perovskite structure. Fourier Transform Infrared Spectroscopy (FTIR) spectra indicated the presence of the fingerprint region of perovskite (ABO 3−δ ) structure. Scanning Electron Microscopy (SEM) images revealed uniformly diffused, micro porous and agglomerated morphology. Differential Thermal Analysis (DTA) and Thermogravimetry (TGA) verified the formation of intermediate metal carbonates that were decomposed to the final product. Nyquist plots against frequency (20 Hz-3 MHz) revealed single semi-circular arcs. The arc showed significant grain boundary contribution to total electrical conduction behaviour of BSCF material synthesized by CMHM and co-precipitation methods. Modulus analysis showed the Debye type conductivity relaxation in CMHM synthesized material. The AC conductivity graphs followed Jonscher's power law. Temperature dependent (RT to 600°C; 10 kHz) impedances showed decreasing trend that was an indication of thermally activated conduction process. A Correlation was established among structural and electrical conduction properties. Hydrothermally synthesized BSCF samples exhibited minimum impedances and maximum AC conductivity, which makes them a potential candidate for cathode material in (IT-SOFCs) applications.

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“…Ceria based nanocrystalline powders and films are being widely prepared and studied as electrolyte /electrode materials for intermediate temperature solid oxide fuel cells (ITSOFCs) [1][2]. The ceria has advantage over other materials due to its stable structure.…”

Section: Introductionmentioning

confidence: 99%

Structural and electrical studies of mixed metal/ceramic composite dielectric thin films

Abdullah

Munir

Saleemi

et al. 2015

2015 Joint IEEE International Symposium on the Applications of Ferroelectric (ISAF), International Symposium on Integrated Func

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Cerium oxide (Rare earth oxide ceramic) films were coated on ITO glass slides where CeO 2 was obtained by a simplified sol-gel method. The layer of molten NiO (Metal oxide) was physiosorped on ceria.The synthesis parameters like molarity of the precipitating agent and annealing temperature of the as prepared films were optimized. The X-ray diffraction was used for the confirmation of the phase, crystal structure and determination of crystallite sizes. The morphology of annealed films was studied using atomic force microscopy. The ac electrical measurements were done using LCR meter at room temperature and in frequency range 1 kHz to 3 MHz. The ac conductivity, dielectric constant and dielectric loss were determined using the electrical data.

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Temperature and frequency dependence of transport phenomena in co-doped rare earth oxides nanoparticles for ITSOFCs

Cited by 13 publications

References 24 publications

Effect of Pr on the electrical and chemical properties of cerium oxide prepared by combustion method

Effect of Pr on the electrical and chemical properties of cerium oxide prepared by combustion method

Reduced impedance in dual substituted strontium cobaltite nanoparticles for renewable energy applications

Structural and electrical studies of mixed metal/ceramic composite dielectric thin films

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