(Invited) Defect Chemistry of Mixed Conducting Oxides for SOFC Cathode

2012 ◽  
Vol 45 (1) ◽  
pp. 377-387 ◽  
Author(s):  
X.-D. Zhou
Keyword(s):  
Defect Chemistry ◽  
Sofc Cathode ◽  
Conducting Oxides

Defect chemistry and physical properties of transparent conducting oxides in the CdO-In2O3-SnO2 system

2002 ◽  
Vol 411 (1) ◽  
pp. 106-114 ◽  
Author(s):  
T.O. Mason ◽  
G.B. Gonzalez ◽  
D.R. Kammler ◽  
N. Mansourian-Hadavi ◽  
B.J. Ingram
Keyword(s):  
Physical Properties ◽  
Transparent Conducting Oxides ◽  
Defect Chemistry ◽  
Conducting Oxides ◽  
Transparent Conducting

(Invited) Methodologies for Characterizing Mixed Conducting Oxides for Oxygen Membrane and SOFC Cathode Application

2012 ◽  
Vol 45 (1) ◽  
pp. 251-264
Author(s):  
P. V. Hendriksen ◽  
M. Sogaard ◽  
P. Plonczak
Keyword(s):  
Sofc Cathode ◽  
Conducting Oxides ◽  
Oxygen Membrane

scholarly journals The Chemical Capacitance as a Fingerprint of Defect Chemistry in Mixed Conducting Oxides

2016 ◽  
pp. 509-518 ◽  
Author(s):  
Fleig Juergen ◽  
Alexander Schmid ◽  
Ghislain M. Rupp ◽  
Christoph Slouka ◽  
Edvinas Navickas ◽  
...  
Keyword(s):  
Defect Chemistry ◽  
Conducting Oxides

scholarly journals Defect chemistry and transport properties of BaxCe0.85M0.15O3-δ

2004 ◽  
Vol 19 (8) ◽  
pp. 2366-2376 ◽  
Author(s):  
J. Wu ◽  
L.P. Li ◽  
W.T.P. Espinosa ◽  
S.M. Haile
Keyword(s):  
Transport Properties ◽  
Elevated Temperatures ◽  
Defect Chemistry ◽  
Gravimetric Analysis ◽  
Barium Cerate ◽  
Charge Balance ◽  
Conducting Oxides ◽  
A Site ◽  
Charged Defects ◽  
Positively Charged

The site-incorporation mechanism of M3+ dopants into A2+B4+O3 perovskites controls the overall defect chemistry and thus their transport properties. For charge-balance reasons, incorporation onto the A2+-site would require the creation of negatively charged point defects (such as cation vacancies), whereas incorporation onto the B4+-site is accompanied by the generation of positively charged defects, typically oxygen vacancies. Oxygen-vacancy content, in turn, is relevant to proton-conducting oxides in which protons are introduced via the dissolution of hydroxyl ions at vacant oxygen sites. We propose here, on the basis of x-ray powder diffraction studies, electron microscopy, chemical analysis, thermal gravimetric analysis, and alternating current impedance spectroscopy, that nominally B-site doped barium cerate can exhibit dopant partitioning as a consequence of barium evaporation at elevated temperatures. Such partitioning and the presence of significant dopant concentrations on the A-site negatively impact proton conductivity. Specific materials examined are BaxCe0.85M0.15O3-δ (x = 0.85 - 1.20; M = Nd, Gd, Yb). The compositional limits for the maximum A-site incorporation are experimentally determined to be: (Ba0.919Nd0.081)(Ce0.919Nd0.081)O3, (Ba0.974Gd0.026)(Ce0.872Gd0.128)O2.875, and Ba(Ce0.85Yb0.15)O2.925. As a consequence of the greater ability of larger cations to exist on the Ba site, the H2O adsorption and proton conductivities of large-cation doped barium cerates are lower than those of small-cation doped analogs.

Dislocations, Ordering and Antiferromagnetic Domains in MnO

1970 ◽  
Vol 28 ◽  
pp. 522-523
Author(s):  
D. J. Barber ◽  
R. G. Evans
Keyword(s):  
Electron Diffraction ◽  
Single Crystal ◽  
Optical Microscopy ◽  
Defect Chemistry ◽  
Magnetic Structures ◽  
Optically Transparent ◽  
Magnetic Features ◽  
Antiferromagnetic Domains

Manganese (II) oxide, MnO, in common with CoO, NiO and FeO, possesses the NaCl structure and shows antiferromagnetism below its Neel point, Tn∼ 122 K. However, the defect chemistry of the four oxides is different and the magnetic structures are not identical. The non-stoichiometry in MnO2 small (∼2%) and below the Tn the spins lie in (111) planes. Previous work reported observations of magnetic features in CoO and NiO. The aim of our work was to find explanations for certain resonance results on antiferromagnetic MnO.Foils of single crystal MnO were prepared from shaped discs by dissolution in a mixture of HCl and HNO3. Optical microscopy revealed that the etch-pitted foils contained cruciform-shaped precipitates, often thick and proud of the surface but red-colored when optically transparent (MnO is green). Electron diffraction and probe microanalysis indicated that the precipitates were Mn2O3, in contrast with recent findings of Co3O4 in CoO.

Interaction of H2O, O2 and H2 with Proton Conducting Oxides Based on Lanthanum Scandates

2019 ◽  
pp. 88-100
Author(s):  
A. S. Farlenkov ◽  
N. A. Zhuravlev ◽  
Т. A. Denisova ◽  
М. V. Ananyev
Keyword(s):  
Water Vapor ◽  
Partial Pressure ◽  
Gas Phase ◽  
Molecular Hydrogen ◽  
Proton Magnetic Resonance ◽  
Partial Pressure Of Oxygen ◽  
Proton Conducting ◽  
Conducting Oxides ◽  
Temperature Range ◽  
Apparent Level

The research uses the method of high-temperature thermogravimetric analysis to study the processes of interaction of the gas phase in the temperature range 300–950 °C in the partial pressure ranges of oxygen 8.1–50.7 kPa, water 6.1–24.3 kPa and hydrogen 4.1 kPa with La1–xSrxScO3–α oxides (x = 0; 0.04; 0.09). In the case of an increase in the partial pressure of water vapor at a constant partial pressure of oxygen (or hydrogen) in the gas phase, the apparent level of saturation of protons is shown to increase. An increase in the apparent level of saturation of protons of the sample also occurs with an increase in the partial pressure of oxygen at a constant partial pressure of water vapor in the gas phase. The paper discusses the causes of the observed processes. The research uses the hydrogen isotope exchange method with the equilibration of the isotope composition of the gas phase to study the incorporation of hydrogen into the structure of proton-conducting oxides based on strontium-doped lanthanum scandates. The concentrations of protons and deuterons were determined in the temperature range of 300–800 °C and a hydrogen pressure of 0.2 kPa for La0.91Sr0.09ScO3–α oxide. The paper discusses the role of oxygen vacancies in the process of incorporation of protons and deuterons from the atmosphere of molecular hydrogen into the structure of the proton conducting oxides La1–xSrxScO3–α (x = 0; 0.04; 0.09). The proton magnetic resonance method was used to study the local structure in the temperature range 23–110 °C at a rotation speed of 10 kHz (MAS) for La0.96Sr0.04ScO3–α oxide after thermogravimetric measurements in an atmosphere containing water vapor, and after exposures in molecular hydrogen atmosphere. The existence of proton defects incorporated into the volume of the investigated proton oxide from both the atmosphere containing water and the atmosphere containing molecular hydrogen is unambiguously shown. The paper considers the effect of the contributions of the volume and surface of La0.96Sr0.04ScO3–α oxide on the shape of the proton magnetic resonance spectra.

Design and Characterization of LSM-ScCeSZ Nanocomposite as MIEC Material for SOFC Cathode and Oxygen-separation Membranes

2008 ◽  
Author(s):  
Vladislav A. Sadykov ◽  
Vitalii Muzykantov ◽  
Aleksei Bovin ◽  
Lubsan Batuev ◽  
Galina Alikina ◽  
...  
Keyword(s):  
Oxygen Separation ◽  
Sofc Cathode ◽  
Separation Membranes
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