The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform
S C Singhal - One of the best experts on this subject based on the ideXlab platform.
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electrochemical vapor deposition of Yttria Stabilized Zirconia films
Journal of The Electrochemical Society, 1990Co-Authors: S C SinghalAbstract:Tubular solid oxide fuel cells employ Yttria-Stabilized Zirconia electrolyte film as an oxygen ion conductor at high temperatures. These Yttria-Stabilized Zirconia electrolyte films are deposited by an electrochemical vapor deposition (EVD) process. The electrochemical transport of oxygen ions during the EVD process is analyzed by measuring the film growth as a function of EVD reaction time; the film growth is found to be parabolic with time. Wagner's transport theory for parabolic growth and the defect model for Yttria-Stabilized Zirconia have been used to calculate the average electronic transport number and the partial electronic conductivity of the electrolyte film. The analysis of the data revealed that the electrolyte film growth is controlled by diffusion of electrons. It is also shown that the electrochemical transport that occurs during EVD of the electrolyte is similar to the phenomena of oxygen semipermeability wherein electrons migrate from the low-oxygen partial pressure site to the high-oxygen partial pressure side, and oxygen ions migrate in the reverse direction maintaining charge neutrality
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Electrochemical Vapor Deposition of Yttria‐Stabilized Zirconia Films
Journal of The Electrochemical Society, 1990Co-Authors: S C SinghalAbstract:Tubular solid oxide fuel cells employ Yttria-Stabilized Zirconia electrolyte film as an oxygen ion conductor at high temperatures. These Yttria-Stabilized Zirconia electrolyte films are deposited by an electrochemical vapor deposition (EVD) process. The electrochemical transport of oxygen ions during the EVD process is analyzed by measuring the film growth as a function of EVD reaction time; the film growth is found to be parabolic with time. Wagner's transport theory for parabolic growth and the defect model for Yttria-Stabilized Zirconia have been used to calculate the average electronic transport number and the partial electronic conductivity of the electrolyte film. The analysis of the data revealed that the electrolyte film growth is controlled by diffusion of electrons. It is also shown that the electrochemical transport that occurs during EVD of the electrolyte is similar to the phenomena of oxygen semipermeability wherein electrons migrate from the low-oxygen partial pressure site to the high-oxygen partial pressure side, and oxygen ions migrate in the reverse direction maintaining charge neutrality
Dmytro Demirskyi - One of the best experts on this subject based on the ideXlab platform.
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Flash spark plasma sintering of ultrafine Yttria-Stabilized Zirconia ceramics
Scripta Materialia, 2016Co-Authors: Oleg Vasylkiv, Hanna Borodianska, Yoshio Sakka, Dmytro DemirskyiAbstract:© 2016 Elsevier Ltd. All rights reserved. The microstructure evolution during high heating rate 'flash' spark plasma sintering (SPS) of ultrafine Yttria-Stabilized Zirconia powder is presented. Consolidation during SPS took place in a single-stage, the activation of preferable interaggregate densification, and thus preserving microstructural features of initial powder. Different sintering stages were identified during conventional SPS, showing a distinctive role of processing temperature. An explanation and analysis of the driving forces behind these observations was attempted.
Jørgen Bøttiger - One of the best experts on this subject based on the ideXlab platform.
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Effects of dopant concentration and impurities on the conductivity of magnetron-sputtered nanocrystalline Yttria-Stabilized Zirconia
Solid State Ionics, 2010Co-Authors: Michael Sillassen, Per Eklund, Nini Pryds, Jørgen BøttigerAbstract:Cubic Yttria-Stabilized Zirconia (YSZ) films with Yttria concentrations of 8.7, 9.9, and 11 mol% have been deposited by reactive pulsed DC magnetron from Zr-Y alloy targets. The overall microstruct ...
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Ionic conductivity and thermal stability of magnetron-sputtered nanocrystalline Yttria-Stabilized Zirconia
Journal of Applied Physics, 2009Co-Authors: Michael Sillassen, Per Eklund, M. Sridharan, Nini Pryds, Nikolaos Bonanos, Jørgen BøttigerAbstract:Thermally stable, stoichiometric, cubic Yttria-Stabilized Zirconia (YSZ) thin-film electrolytes have been synthesized by reactive pulsed dc magnetron sputtering from a Zr-Y (80/20 at. %) alloy targ ...
Guillermo Aguilar - One of the best experts on this subject based on the ideXlab platform.
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transparent nanocrystalline Yttria Stabilized Zirconia calvarium prosthesis
Nanomedicine: Nanotechnology Biology and Medicine, 2013Co-Authors: Yasaman Damestani, Carissa L Reynolds, Yasuhiro Kodera, Devin K Binder, Hyle B Park, Javier E Garay, Guillermo AguilarAbstract:Abstract Laser-based diagnostics and therapeutics show promise for many neurological disorders. However, the poor transparency of cranial bone (calvaria) limits the spatial resolution and interaction depth that can be achieved, thus constraining opportunity in this regard. Herein, we report preliminary results from efforts seeking to address this limitation through use of novel transparent cranial implants made from nanocrystalline Yttria-Stabilized Zirconia (nc-YSZ). Using optical coherence tomography (OCT) imaging of underlying brain in an acute murine model, we show that signal strength is improved when imaging through nc-YSZ implants relative to native cranium. As such, this provides initial evidence supporting the feasibility of nc-YSZ as a transparent cranial implant material. Furthermore, it represents a crucial first step towards realization of an innovative new concept we are developing, which seeks to eventually provide a clinically-viable means for optically accessing the brain, on-demand, over large areas, and on a chronically-recurring basis, without need for repeated craniectomies. From the Clinical Editor In this study, transparent nanocrystalline Yttria-Stabilized-Zirconia is used as an experimental “cranium prosthesis” material, enabling the replacement of segments of cranial bone with a material that allows for optical access to the brain on a recurrent basis using optical imaging methods such as OCT.
Z A Munir - One of the best experts on this subject based on the ideXlab platform.
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on the conduction pathway for protons in nanocrystalline Yttria Stabilized Zirconia
Physical Chemistry Chemical Physics, 2009Co-Authors: Hugo J Avilaparedes, Shizhong Wang, Chienting Chen, Roger A De Souza, Manfred Martin, Z A MunirAbstract:In this communication we elucidate a microstructural picture of proton conduction in nano-crystalline Yttria-Stabilized Zirconia at low temperatures (Kim et al. Adv. Mater., 2008, 20, 556). Based on careful analysis of electrical impedance spectra obtained from samples with grain sizes of ∼13 and ∼100 nm under both wet and dry atmospheres over a wide range of temperatures (room temperature–500 °C), we were able to identify the pathway for proton conduction in this material. It was found that the grain boundaries in nano-crystalline Yttria-Stabilized Zirconia are highly selective for ion transport, being conductive for proton transport but resistive for oxygen-ion transport.
