Oxygen potentials of PuO2-x

2012 ◽  
Vol 1444 ◽  
Author(s):  
Akira Komeno ◽  
Masato Kato ◽  
Shun Hirooka ◽  
Takeo Sunaoshi
Keyword(s):  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Measurement Data ◽  
Approximate Equation ◽  
Defect Chemistry ◽  
Thermo Gravimetry ◽  
Metal Ratio ◽  
The Relationship

ABSTRACTOxygen potentials of PuO2-x were measured at temperatures of 1473 - 1873 K by thermo-gravimetry. The oxygen potentials were determined by in situ analysis as functions of oxygen-to-metal ratio and temperature. The measurement data were analyzed on the basis of defect chemistry and an approximate equation was derived to represent the relationship among temperature, oxygen partial pressure, and deviation x in PuO2-x.

Characterization of YBa2Cu4O8 high temperature electrical properties and thermodynamic stability

1991 ◽  
Vol 6 (10) ◽  
pp. 2054-2058 ◽  
Author(s):  
B-S. Hong ◽  
T.O. Mason
Keyword(s):  
High Temperature ◽  
Electrical Property ◽  
Electrical Properties ◽  
Seebeck Coefficient ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Pressure Range ◽  
Stability Range

Via in situ electrical property measurements (conductivity, Seebeck coefficient) over the temperature range 500–800 °C and oxygen partial pressure range 10−4-1 atm, the equilibrium transport properties and stability range of YBa2Cu4O8 were determined. YBa2Cu4O8 behaves like the intrinsically mixed-valent compound, magnetite (Fe3O4), with small variations in electrical properties with changes in oxygen partial pressure. The decomposition boundary to YBa2Cu3O6+y (or YBa2Cu3.5O7.5±z) and CuO occurs at log(po2, atm) = −1.24 × 104/T(K) + 11.01(773 ⋚ T(K) ⋚ 1073).

Effect of O2 Partial Pressure on Post Annealed Ba2YCU3O7-δ Thin Films

1992 ◽  
Vol 275 ◽  
Author(s):  
Julia M. PhUlips ◽  
M. P. Siegal ◽  
S. Y. Hou ◽  
T. H. Tiefel ◽  
J. H. Marshall
Keyword(s):  
Partial Pressure ◽  
Film Growth ◽  
Epitaxial Films ◽  
Pinning Force ◽  
Low Oxygen ◽  
O2 Partial Pressure ◽  
Growth Method ◽  
Lower Temperature ◽  
The Relationship

ABSTRACTEpitaxial films of Ba2YCu3O7-δ (BYCO) as thin as 250 å A and with Jc's approaching those of the best in situ grown films can be formed by co-evaporating BaF2, Y, and Cu followed by a two-stage anneal. These results extend the work on films > 2000 Å thick by R. Feenstra et al. [J. Appl. Phys. 69, 6569 (1991)]. High quality films of these thicknesses become possible if low oxygen partial pressure [p(O2) = 4.3 Torr] is used during the high temperature portion cf the anneal (Ta). The BYCO melt line is the upper limit for Ta. The use of low p(O2) shifts the window for stable BYCO film growth to lower temperature, which allows the formation of smooth films with greater microstructural disorder than is found in films grown in p(O2) = 740 Torr at higher Ta. The best films annealed in p(O2)=4.3 Torr have Jc values a factor of four higher than do comparable films annealed in P2=740 Torr. The relationship between the T required to grow films with the strongest pinning force and p(O2) is log independent of growth method (in situ or situ) over a range of five orders of magnitude of P(O2).

Influences of oxygen impurity contained in nitrogen gas on the reactions of chromium with nitrogen

2005 ◽  
Vol 20 (10) ◽  
pp. 2745-2753 ◽  
Author(s):  
Yung-Shou Ho ◽  
Fong-Shung Huang ◽  
Fu-Hsing Lu
Keyword(s):  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Oxygen Impurity ◽  
Nitrogen Gas ◽  
Available Nitrogen ◽  
Increasing Temperature ◽  
Pressure Changes ◽  
Annealing Experiments ◽  
Simultaneous Dissolution

In this research, the influences of the oxygen impurity contained in the commercially available nitrogen gas on the reactions of chromium pellets with nitrogen were investigated in the temperature range 600–1350 °C. A small amount of oxygen competed with the majority N2 to react with chromium in the annealing process. Analyzing the in situ oxygen partial pressure changes during annealing proved that the dissolution of oxygen in Cr and/or resultant CrxN (CrN or Cr2N) was exothermic and the solubility decreased with increasing temperature. It was found that the oxygen partial pressure decreased drastically to about 10−22 atm when specimens were annealed at 600 °C compared to a mere 10−5 atm for a blank test, while its value increased with temperature. The oxidation involved simultaneous dissolution of oxygen in specimens and formation of oxide scale. Moreover, comparing the aforementioned results with those obtained from additional annealing experiments preformed in argon gas showed that the formation of Cr2O3 might stem mainly from oxidation of the resultant nitrides instead of the metallic chromium.

Defect chemistry of donor-doped BaTiO3 with BaO-excess for reduction resistant PTCR thermistor applications – redox-behaviour

2020 ◽  
Vol 22 (15) ◽  
pp. 8219-8232
Author(s):  
Christian Pithan ◽  
Hayato Katsu ◽  
Rainer Waser
Keyword(s):  
Electrical Conductivity ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Defect Chemistry ◽  
Redox Behaviour ◽  
Ptcr Effect

The electrical conductivity of donor-doped BaTiO3 thermistor ceramics with excessive BaO revealing a reduction-persistent PTCR effect has been carefully examined depending on materials’ composition and oxygen partial pressure at moderate temperatures between 973 and 1273 K.

In Situ Deposition of YBCO Thin Films by Sputtering under Low Oxygen Partial Pressure

1994 ◽  
Vol 33 (Part 2, No. 5B) ◽  
pp. L718-L721 ◽  
Author(s):  
Yong Ki Park ◽  
Keunseop Park ◽  
Soon-Gul Lee ◽  
Dong Chan Shin ◽  
Jong-Chul Park
Keyword(s):  
Thin Films ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Low Oxygen ◽  
Ybco Thin Films ◽  
In Situ Deposition

Oxygen partial pressure dependence of in situ X-ray absorption spectroscopy at the Co and Fe K edges for (La0.6Sr0.4)(Co0.2Fe0.8)O3−δ

2012 ◽  
Vol 152 (4) ◽  
pp. 278-283 ◽  
Author(s):  
Takanori Itoh ◽  
Saori Shirasaki ◽  
Hironori Ofuchi ◽  
Sayaka Hirayama ◽  
Tetsuo Honma ◽  
...  
Keyword(s):  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Absorption Spectroscopy ◽  
Pressure Dependence ◽  
X Ray ◽  
X Ray Absorption
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