Electronic Conductivity of ZrO[sub 2]–CeO[sub 2]–YO[sub 1.5] Solid Solutions in a Wide Range of Temperature and Oxygen Partial Pressure

2006 ◽  
Vol 153 (12) ◽  
pp. A2198 ◽  
Author(s):  
Yueping Xiong ◽  
Katsuhiko Yamaji ◽  
Natsuko Sakai ◽  
Haruo Kishimoto ◽  
Teruhisa Horita ◽  
...  
Keyword(s):  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Solid Solutions ◽  
Electronic Conductivity ◽  
Wide Range

scholarly journals Electrical Characterization of La2-xSrxCuO4-y Superconductors

1989 ◽  
Vol 44 (1) ◽  
pp. 26-28 ◽  
Author(s):  
G. Chiodelli ◽  
G. Campari-Viganò ◽  
V. Massarotti ◽  
G. Flor
Keyword(s):  
Electrical Resistivity ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Solid Solutions ◽  
Electrical Characterization ◽  
Superconducting Transition ◽  
Electrical Behaviour ◽  
Temperature Range

Abstract The electrical behaviour of La2-xSrxCuO4-y solid solutions (with x = 0, x = 0.025, x = 0.05, and x = 0.15) at temperatures between 10 and 900 K and under different oxygen partial pressure pO2 = 1 ÷ 10-6 atm) has been investigated. The samples prepared and measured under an O2 flux (i.e., with y = 0) show a superconducting transition with Tc = 46, 29. 37 K for x = 0. 0.05 and 0.15, respectively. The samples with x = 0.025, y = 0, and x = 0, y ≠ 0 exhibit no sign of superconductivity. In the temperature range 100-900 K. La2CuO4 is semiconducting, whereas the electrical resistivity is independent of temperature for the x =0.025 sample, and the x = 0.05 and x = 0.15 are metallic.

Mixed Conducting and Cathodic Properties of Zirconia-Nio Mixture

1998 ◽  
Vol 548 ◽  
Author(s):  
Y. M. Park ◽  
G. M. Choi
Keyword(s):  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Pressure Dependence ◽  
Composition Range ◽  
Porous Electrode ◽  
Electronic Conductivity ◽  
Electronic Contribution ◽  
Stabilized Zirconia ◽  
Wide Composition Range ◽  
Ysz Electrolyte

AbsractStabilized zirconia-NiO mixture was chosen as a representative of ionic-electronic composite and the effect of mixture composition on the mixed conducting properties were studied. The measurements of oxygen partial-pressure dependence of conductivity and Hebb-Wagner polarization enabled to determine the electronic contribution to the total conduction in a wide composition range. In ion conduction region, electronic conductivity increased continuously with NiO content. The overpotentials of screen-printed YSZ-NiO electrode on YSZ electrolyte were measured and found to decrease with increasing NiO content and thus with the estimated electronic conductivity of porous electrode.

scholarly journals Solid Solutions in the System Fe1-xO/ZnO at Low Oxygen Partial Pressure 

2010 ◽  
Vol 636 (9-10) ◽  
pp. 1880-1885 ◽  
Author(s):  
Sebastian Moll ◽  
Sven-Ulf Weber ◽  
Klaus-Dieter Becker ◽  
Werner Mader
Keyword(s):  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Solid Solutions ◽  
Low Oxygen

Impact of oxygen content on preferred localization of p- and n-type carriers in La0.5Sr0.5Fe1−xMnxO3−δ

2021 ◽  
Author(s):  
Sergey S. Nikitin ◽  
Alexey A. Markov ◽  
Oleg V. Merkulov ◽  
Andrey V Chukin ◽  
Mikhail Patrakeev
Keyword(s):  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Oxygen Content ◽  
Coulometric Titration ◽  
Defect Chemistry ◽  
Wide Range

The oxygen content in La0.5Sr0.5Fe1−xMnxO3−δ, measured by coulometric titration in a wide range of oxygen partial pressure at various temperatures, was used for defect chemistry analysis. The obtained data were...

New Results for Electron Transport, Chemical Diffusion and Stability of Solid Oxygen Ion Conductors

2002 ◽  
Vol 756 ◽  
Author(s):  
H.-D. Wiemhoefer ◽  
M. Dogan ◽  
S. Luebke ◽  
V. Ruehrup
Keyword(s):  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Electronic Conductivity ◽  
Chemical Diffusion ◽  
Solid Oxide ◽  
Lanthanum Gallate ◽  
Good Resolution ◽  
Strong Concentration ◽  
Valence States ◽  
Band Tailing

ABSTRACTWe describe the measurement of electronic conductivity of solid oxide electrolytes by a modified Hebb-Wagner technique based on the use of blocking microelectrodes. Results are presented for a couple of typical solid oxide electrolyte systems mainly derived from ceria and lanthanum gallate. The examples demonstrate a good resolution of the microelectrode technique in particular within the electrolyte domain, i.e. around the minimum of the electronic conductivity. This made possible the detection of deviations from the predicted oxygen partial pressure dependence of simple defect models for the concentrations of electrons and holes. The observed deviations from these defect models, at least partially, reflect the overemphasized ideality of the usually applied semiconductor model.Whereas the effect of dissolved transition metals with variable valence states such as Fe, and Co on the electronic conduction is well known, it was unexpected to find a strong concentration dependent effect of dopants like Y3+ and Zr4+ in ceria or Mg2+ and Sr2+ in the gallates upon the electronic conductivity within the electrolytic domain. Ions like Y3+ and Zr4+ cause a shift and a partial broadening of electronic states in ceria based materials. Indications have been found for band tailing due to high defect concentrations. In some cases, the dopants cause the appearance of additional localized electron states in the gap which give rise to weak superimposed maxima of the electronic conductivity at a particular oxygen partial pressure within the electrolytic domain.Accordingly, one cannot expect that electronic conductivities of solid electrolytes are insensitive to a changing concentration of stabilizers such as Y, Ca, etc. For instance, even a moderate doping of ceria by zirconia leads to a considerable electronic excess conductivity in the electrolytic domain.

scholarly journals Mass loss of platinum-rhodium thermocouple wires at 1324°C

2021 ◽  
Author(s):  
Sivahami Uthayakumaar ◽  
Stuart Davidson ◽  
Jonathan Pearce
Keyword(s):  
High Temperature ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Mass Loss ◽  
High Temperatures ◽  
High Precision ◽  
Elapsed Time ◽  
Mass Losses ◽  
Wide Range

It is known that Pt-Rh thermocouples exhibit mass loss when in the presence of oxygen at high temperatures due to the formation of volatile oxides of Pt and Rh. The mass losses of Pt, Pt-6%Rh and Pt-30%Rh wires, commonly used for thermocouples, were considered in this paper to characterise the mass loss of wires of the three compositions due to formation and evaporation of the oxides PtO2 and RhO2 under the conditions that would be seen by thermocouples used at high temperature. For the tests, the wires were placed in thin alumina tubes to emulate the thermocouple format, and the measurements were performed in air at a temperature of 1324 °C, i.e. with oxygen partial pressure of 21.3 kPa. It was found that the mass loss of the three wires increases linearly with elapsed time, consistent with other investigations, up to an elapsed time of about 150 hours, but after that, a marked acceleration of the mass loss is observed. Remarkably, previous high precision studies have shown that a cross-over after about 150 hours at 1324 °C is also observed in the thermoelectric drift of a wide range of Pt-Rh thermocouples, and the current results are compared with those studies. The mass loss was greatest for Pt-30%Rh, followed by Pt 6%Rh, then Pt.

Systematic trends of YBa2Cu3O7−δ thin films post annealed in low oxygen partial pressures

1994 ◽  
Vol 9 (8) ◽  
pp. 1936-1945 ◽  
Author(s):  
S.Y. Hou ◽  
Julia M. Phillips ◽  
D.J. Werder ◽  
T.H. Tiefel ◽  
J.H. Marshall ◽  
...  
Keyword(s):  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Low Oxygen ◽  
Normal State Resistivity ◽  
Film Properties ◽  
Ion Channeling ◽  
Partial Pressures ◽  
High Annealing ◽  
Wide Range ◽  
Different Characteristics

Systematic studies have been performed on 1000 Å YBa2Cu3O7−δ films produced by the BaF2 process and annealed in an oxygen partial pressure (Po2) range from 740 Torr to 10 mTorr as well as a temperature range from 600 to 1050 °C. The results show that while high quality films can be annealed in a wide range of oxygen partial pressure, they have different characteristics. In general, crystalline quality and Tc are optimized at high Po2 and high annealing temperature, while strong flux pinning and low normal state resistivity are achieved at lower values of both variables. Under optimized low Po2 conditions, an ion channeling Xmin of 6% is obtained on films as thick as 5000 Å. This study will serve as a useful guide to tailoring film properties to the application at hand.

New Mixed Conductors Based on Doped Layered Perovskites

1998 ◽  
Vol 548 ◽  
Author(s):  
Carlos Navas ◽  
Harry L. Tuller ◽  
Hans-Conrad zur Loye
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Electronic Conductivity ◽  
Total Conductivity ◽  
Mixed Conductors ◽  
Type Conductivity ◽  
P Type ◽  
Layered Perovskites

ABSTRACTA series of doped Ruddlesden-Popper phases, of general formula Sr3Ti2−xMxO7−δ (M=Al, Ga, Co), were synthesized and their electrical conductivity characterized as a function of temperature and oxygen partial pressure. For fixed-valent dopants, p-type conductivity predominates at p(O2)>10−5 atm, followed by a p(O2)-independent electrolytic regime, and n-type electronic conductivity at very low p(O2). The electrolytic regime exhibits activation energies in the range 1.7-1.8 eV. Doping with transition metals such as Co results in a very significant increase in total conductivity with a p-type conductivity at high p(O2). Furthermore, an apparent ionic regime at intermediate p(O2) is observed, characterized by high conductivity (>10−2 S/cm at 700 °C) and low activation energy (0.7 eV). This interpretation is consistent with iodometric measurements as interpreted by a defect chemical model. Other measurements are in progress to confirm this conclusion.

Electrochemical Properties of Ag5Te2Cl0.8Br0.2, a Representative of the Solid Solutions Ag5Te2Cl1–xBrx

2008 ◽  
Vol 63 (9) ◽  
pp. 1083-1086 ◽  
Author(s):  
Melanie Bawohl ◽  
Tom Nilges
Keyword(s):  
Phase Transition ◽  
Transition Temperature ◽  
Phase Space ◽  
Ionic Conductivity ◽  
Phase Transition Temperature ◽  
Solid Solutions ◽  
Electronic Conductivity ◽  
Space Group ◽  
Disorder Phase Transition ◽  
Wide Range

Impedance spectroscopic investigations of Ag5Te2Cl0.8Br0.2, a selected representative of the solid solutions Ag5Te2Cl1−xBrx with x = 0 - 1, proved the mixed-conducting property of this class of materials. Two polymorphs are realized in the temperature range of 309 to 410 K, the monoclinic β - phase (space group P21/n) and the tetragonal α-phase (space group I4/mcm) with an order-disorder phase transition temperature of 336 K (DSC). A sharp increase of the total and ionic conductivity can be observed at 337 K, in good accordance with the phase transition temperature. The electronic conductivity exceeds the ionic conductivity by approximately one order of magnitude over a wide range of temperature. Conductivities are σion = 6.9×10−5 (309 K) and σtot = 4.80×10−4 Ω−1 cm−1 (310 K) for β -Ag5Te2Cl0.8Br0.2 and σion = 1.6×10−2 (395 K) and σtot = 1.73×10−1 Ω−1 cm−1 (394 K) for α-Ag5Te2Cl0.8Br0.2.

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