scholarly journals Space–charge theory applied to the grain boundary impedance of proton conducting BaZr0.9Y0.1O3−δ

2010 ◽  
Vol 181 (5-7) ◽  
pp. 268-275 ◽  
Author(s):  
Christian Kjølseth ◽  
Harald Fjeld ◽  
Øystein Prytz ◽  
Paul Inge Dahl ◽  
Claude Estournès ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Space Charge ◽  
Proton Conducting ◽  
Boundary Impedance

scholarly journals Influence of Ce3+ polarons on grain boundary space-charge in proton conducting Y-doped BaCeO3

2018 ◽  
Vol 20 (23) ◽  
pp. 16209-16215 ◽  
Author(s):  
Jonathan M. Polfus ◽  
Mehdi Pishahang ◽  
Rune Bredesen
Keyword(s):  
Grain Boundary ◽  
Space Charge ◽  
Oxygen Vacancies ◽  
Proton Conducting ◽  
Space Charge Potential ◽  
Charge Potential ◽  
Type Conduction ◽  
Boundary Core ◽  
Boundary Space

Ce3+ polarons associated with oxygen vacancies in the grain boundary core lowers the space-charge potential and may enhance n-type conduction.

Space-charge concepts on grain boundary impedance of a high-purity yttria-stabilized tetragonal zirconia polycrystal

2001 ◽  
Vol 16 (9) ◽  
pp. 2739-2751 ◽  
Author(s):  
Jong-Sook Lee ◽  
Doh-Yeon Kim
Keyword(s):  
Grain Boundary ◽  
Space Charge ◽  
High Purity ◽  
Tetragonal Zirconia ◽  
Impedance Analysis ◽  
Dopant Profile ◽  
Brick Layer Model ◽  
Temperature Equilibrium ◽  
Boundary Impedance ◽  
Tetragonal Zirconia Polycrystal

A detailed impedance analysis using the brick-layer model is performed on a high-purity yttria-stabilized tetragonal zirconia polycrystal (Y-TZP). Space-charge impedance is generally formulated and expressions for the respective space-charge models are therefrom derived depending on whether dopant ions are mobile or immobile. Pronounced yttrium segregation in Y-TZP is also considered in the analysis in that the dopant profile is assumed to be frozen from a high-temperature equilibrium distribution. Comparison with experimental observations shows that the electrically measured grain-boundary thickness corresponds to the Schottky-barrier width, slightly modified by the dopant segregation. The grain-boundary resistance is not consistent with any space-charge models and the strong defect interaction due to the yttrium enrichment is suggested to be mainly responsible.

Surface defect chemistry of Y-substituted and hydrated BaZrO3 with subsurface space-charge regions

2016 ◽  
Vol 4 (19) ◽  
pp. 7437-7444 ◽  
Author(s):  
Jonathan M. Polfus ◽  
Tor S. Bjørheim ◽  
Truls Norby ◽  
Rune Bredesen
Keyword(s):  
Surface Layer ◽  
Space Charge ◽  
Space Charge Region ◽  
First Principles ◽  
Surface Defect ◽  
Surface Defects ◽  
Defect Chemistry ◽  
First Principles Calculations ◽  
Proton Conducting ◽  
Charged Species

First-principles calculations were utilized to elucidate the complete defect equilibria of surfaces of proton conducting BaZrO3, encompassing charged species adsorbed to the surface, defects in the surface layer as well as in the subsurface space-charge region and bulk.

scholarly journals Влияние влажности на электроперенос протонпроводящих перовскитов AZr-=SUB=-0.95-=/SUB=-Sc-=SUB=-0.05-=/SUB=-O-=SUB=-3-alpha-=/SUB=- (A=Ca, Sr, Ba) в окислительной атмосфере

2019 ◽  
Vol 61 (4) ◽  
pp. 645
Author(s):  
В.Б. Балакирева ◽  
В.П. Горелов ◽  
Л.А. Дунюшкина ◽  
А.В. Кузьмин
Keyword(s):  
Impedance Spectroscopy ◽  
Grain Boundary ◽  
General Formula ◽  
Considerable Effect ◽  
Humid Atmosphere ◽  
Proton Conducting ◽  
Hydronium Ion ◽  
The Impact

AbstractThe total, bulk, and grain boundary conductivities of proton-conducting zirconates of general formula AZr_0.95Sc_0.05O_3 – α (AZS), where A = Ca, Sr, Ba, are measured in air with different humidity levels. The conductivity is measured using the four-probe dc method (600–900°C) and impedance spectroscopy (30–800°C). The impact of humid atmosphere on the total, bulk, and grain boundary conductivities of the AZS system is studied at different humidity levels: $${{p}_{{{{{\text{H}}}_{{\text{2}}}}{\text{O}}}}}$$ = 0.04, 0.61, and 2.5 kPa. Humidity is found to have a considerable effect on the conductivity of our CaZS and BaZS at lower temperatures, suggesting the likelihood of hydronium ion-mediated transport.

On determining the height of the potential barrier at grain boundaries in ion-conducting oxides

2016 ◽  
Vol 18 (4) ◽  
pp. 3023-3031 ◽  
Author(s):  
Sangtae Kim ◽  
Seong K. Kim ◽  
Sergey Khodorov ◽  
Joachim Maier ◽  
Igor Lubomirsky
Keyword(s):  
Grain Boundary ◽  
Space Charge ◽  
Grain Boundaries ◽  
Potential Barrier ◽  
Boundary Resistance ◽  
Resistivity Ratio ◽  
Linear Diffusion ◽  
Conducting Oxides ◽  
Ion Conducting

Combining the linear diffusion and resistivity ratio models, one can distinguish the grain boundary resistance related to space charge from the resistance from other sources.

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