Oxidation Kinetics of Yba2Cu3OT7-x Thin Films in the Presence of Atomic Oxygen and Molecular Oxygen by In-Situ Resistivity Measurement

1991 ◽  
Vol 230 ◽  
Author(s):  
K. Yamamoto ◽  
B. M. Lairson ◽  
J. C. Bravman ◽  
T. H. Geballe
Keyword(s):  
Thin Films ◽  
Molecular Oxygen ◽  
Atomic Oxygen ◽  
Resistivity Measurement ◽  
Oxygen Stoichiometry ◽  
Ambient Conditions ◽  
Kinetics Of Oxidation ◽  
Thermally Activated ◽  
Kinetics Of

AbstractThe kinetics of oxidation in Yba2Cu3O7-x thin films in the presence of molecular and atomic oxygen ambients have been studied. The resistivity of c-axis, a-axis, and mixed a+c axis oriented films, deposited in-situ by off-axis magnetron sputtering, was measured as a function of time subsequent to a change in the ambient conditions. The oxidation process is shown to be thermally activated and can be characterized by a diffusion model with an activation energy which varies from approximately 1.2eV in the presence of molecular oxygen to 0.6eV for a flux of 2×1015 oxygen atoms/cm2sec. In both cases, diffusivity is found to be insensitive to oxygen stoichiometry, but the rate of oxidation is found to be sensitive to the microstructure and orientation of the films.

Kinetics of Ion-Exchange Reactions in Hybrid Organic–Inorganic Perovskite Thin Films Studied by In Situ Real-Time X-ray Scattering

2018 ◽  
Vol 9 (23) ◽  
pp. 6750-6754 ◽  
Author(s):  
Alessandro Greco ◽  
Alexander Hinderhofer ◽  
M. Ibrahim Dar ◽  
Neha Arora ◽  
Jan Hagenlocher ◽  
...  
Keyword(s):  
Thin Films ◽  
Ion Exchange ◽  
Real Time ◽  
Exchange Reactions ◽  
Inorganic Perovskite ◽  
X Ray ◽  
X Ray Scattering ◽  
Kinetics Of ◽  
Kinetics Of Ion Exchange

In situ high temperature X-ray diffraction study of the kinetics of phase separation in the uranium-plutonium mixed oxide (U0.55Pu0.45)O2-x

2014 ◽  
Vol 1645 ◽  
Author(s):  
Romain VAUCHY ◽  
Renaud.C. BELIN ◽  
Anne-Charlotte ROBISSON ◽  
Fiqiri HODAJ
Keyword(s):  
Phase Separation ◽  
Room Temperature ◽  
Mixed Oxides ◽  
Oxygen Stoichiometry ◽  
X Ray Diffraction ◽  
Fundamental Interest ◽  
X Ray ◽  
Uranium Plutonium ◽  
Kinetics Of

ABSTRACTUranium-plutonium mixed oxides incorporating high amounts of plutonium are considered for future nuclear reactors. For plutonium content higher than 20%, a phase separation occurs, depending on the temperature and on the oxygen stoichiometry. This phase separation phenomenon is still not precisely described, especially at high plutonium content. Here, using an original in situ fast X-ray diffraction device dedicated to radioactive materials, we evidenced a phase separation occurring during rapid cooling from 1773 K to room temperature at the rate of 0.05 and 2 K per second for a (U0.55Pu0.45)O2-x compound under a reducing atmosphere. The results show that the cooling rate does not impact the lattice parameters of the obtained phases at room temperature but their fraction. In addition to their obvious fundamental interest, these results are of utmost importance in the prospect of using uranium-plutonium mixed oxides with high plutonium content as nuclear fuels.

scholarly journals Oxygen in Complex Oxide Thin Films Grown by Pulsed Laser Deposition: a Perspective

2019 ◽  
Vol 33 (1) ◽  
pp. 205-212 ◽  
Author(s):  
Gertjan Koster ◽  
Dave H. A. Blank ◽  
Guus A. J. H. M. Rijnders
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Complex Oxide ◽  
Laser Deposition ◽  
Oxygen Stoichiometry ◽  
Oxide Thin Films ◽  
Film Synthesis ◽  
Kinetics Of ◽  
Oxidation Mechanisms

Abstract For thin film synthesis of complex oxides, one of the most important issues has always been how to oxidise the material. For a technique like pulsed laser deposition, a key benefit is the relatively high oxygen background pressure one can operate at, and therefor oxidation should be relatively straightforward. However, understanding the microscopic oxidation mechanisms turns out to be rather difficult. In this perspective, we give a brief overview of the sources of oxidation for complex oxide thin films grown by pulsed laser deposition. While it is clear what these sources are, their role in the kinetics of the formation of the crystal structure and oxygen stoichiometry is not fully understood.

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