Grain boundary scavenging through reactive sintering of strontium and iron in samarium doped ceria electrolyte for ITSOFC applications

Sudarsan, Preethi; Moorthy, Suresh Babu Krishna

doi:10.1016/j.materresbull.2017.12.047

Cited by 23 publications

(6 citation statements)

References 58 publications

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“…23,24 An increase in density and decrease in conductivity is reported for the co-doping of strontium and iron in samarium (20 mol.%)-doped ceria, which underwent reactive sintering at 1300°C. 25 But, Villas-Boas et al reported that the addition of 1 mol.% of Zn(NO 3 ) 2 on Gd-doped ceria produced a slight increase in n-type electronic conductivity with a reduction in sintering temperature by 100°C. 26 From these studies, it can be concluded that the addition of low-melting-point oxides of cations with a different coordination number, electronegativity and valency can effectively decrease the sintering temperature of ceramic systems.…”

Section: Introductionmentioning

confidence: 99%

Impedance Spectroscopic Studies of B2O3-Substituted CeO2-Gd2O3 Systems

Priya

Sandhya

Rajendran

2020

Journal of Elec Materi

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In this paper, the change in the conduction mechanism due to B 2 O 3 addition in a ceria-based nanoceramic system is understood by studying the nature of conductivity and the variation of electric modulus function with frequency at different temperatures. The studies revealed that oxide ion conduction in the prepared system is prominent only after 500°C. The activation energy for electrical conduction and oxide ion hopping in the system is found to be 0.26 eV and 0.85 eV, respectively. The discrepancy in the values of the activation energies itself is evidence of a different mechanism other than oxide ion hopping occurring in the present sample. The electric modulus function shows two relaxation peaks at lower temperatures corresponding to short-range and long-range relaxation for the charge carriers. Relaxation energies for the processes are found to be 0.27 eV and 0.95 eV. This is evidence of the occurrence of Maxwell-Wagner relaxation phenomena in the ceramic system. Explicitly, thermally activated oxide ion migration, along with the relaxation of electrons at the site of the bound pair (B-V o) AE is observed in the prepared nanocrystalline system.

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Section: Introductionmentioning

confidence: 99%

Impedance Spectroscopic Studies of B2O3-Substituted CeO2-Gd2O3 Systems

Priya

Sandhya

Rajendran

2020

Journal of Elec Materi

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“…Under a reducing atmosphere, iron oxide (Fe 2 O 3 ) has been reported to reduce to Fe 3 O 4 at 300 °C and then to metallic Fe at 450 °C. 65 The secondary Fe-rich phase, observed in Fig. 7, is prone to reduce and therefore exhibiting a relatively high electronic conductivity, which also decreases the bulk resistance of the Fe-doped CGO samples.…”

Section: Resultsmentioning

confidence: 98%

Interface segregation of iron sintering aid in gadolinium-doped ceria

Machado,

da Silva,

Moraes

et al. 2023

CrystEngComm

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“…The discovery of grain boundary "scavenging" agents, able to combine chemically with impurities/glassy phases, forming isolated particles in joints between grains, like addition of alumina to zirconia-based electrolytes, is a good example of this process. This description, even if more than 40 years old, is still used in many cases to explain grain boundary conductivity improvements (Beekmans and Heyne, 1976;Butler and Drennan, 1982;Guo et al, 1995;Zhang et al, 2004;Sudarsan and Krishnamoorthy, 2018).…”

Section: Grain Boundary Effectsmentioning

confidence: 99%

Role of salts on the electrical performance of ceria-based electrolytes: An overview

Grilo

Jamale²,

Starykevich³

et al. 2022

Front. Mater.

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This work provides an overview on established achievements and debatable findings involving Ca, Gd or Sm-doped ceria-based electrolytes, using Li2CO3, LiNO3 and Na2CO3 as sintering aid or as second phase. The performance of these materials is discussed considering the characteristics of the oxides and of the salts or derived second(ary) phases (e.g., alkali metal oxides and hydroxides, eutectic mixtures), extensively surveyed to identify influential parameters with respect to processing and electrical performance (e.g., melting and boiling points, thermal decomposition, hydrolysis). The analysis of published data highlights the possible contribution of additional charge carriers to the total conductivity, besides oxide-ion vacancies. Claimed bulk and grain boundary conductivity enhancements are deeply discussed, as well as advantages and limitations of impedance spectroscopy as characterization tool. Irrespective of controversial reasons, reports on unusual improvements of grain boundary conductivity sustain the possibility of advanced grain boundary engineering to enhance the performance of these materials.

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Grain boundary scavenging through reactive sintering of strontium and iron in samarium doped ceria electrolyte for ITSOFC applications

Cited by 23 publications

References 58 publications

Impedance Spectroscopic Studies of B2O3-Substituted CeO2-Gd2O3 Systems

Impedance Spectroscopic Studies of B2O3-Substituted CeO2-Gd2O3 Systems

Interface segregation of iron sintering aid in gadolinium-doped ceria

Role of salts on the electrical performance of ceria-based electrolytes: An overview

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