The Experts below are selected from a list of 279 Experts worldwide ranked by ideXlab platform
Yoshio Arai - One of the best experts on this subject based on the ideXlab platform.
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Optimum strain state for Oxygen Diffusion in yttria-stabilised zirconia
Solid State Ionics, 2011Co-Authors: Wakako Araki, Yoshio AraiAbstract:Abstract The strain effect of the Oxygen Diffusion in the yttria-stabilised zirconia in the present study was investigated by means of a molecular dynamics simulation. The simulation was conducted for various parameters such as the strain, temperature, yttria concentration, and potential parameter, and in addition, the biaxial and hydrostatic cases were considered. For a uniaxial strain, the Oxygen Diffusion was enhanced in the tensile direction whereas it was hindered in the compressive direction. The maximum improvement was achieved for a smaller strain at a lower temperature and also with a lower yttria concentration. For the biaxial and hydrostatic strains, the total Diffusion coefficient was enhanced simply as a result of the enhancement when using the uniaxial strain in each direction. The detailed deformation analysis reveals that the optimum strain state for the highest Oxygen Diffusion in the tensile direction can be obtained when the Oxygen ion is largely displaced in the fluorite lattice structure.
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Oxygen Diffusion in Yttria-Stabilized Zirconia Subjected to Mechanical Stress
Defect and Diffusion Forum, 2011Co-Authors: Wakako Araki, Yoshio AraiAbstract:The Oxygen Diffusion in 4, 8, and 14 mol%-yttria-stabilized zirconia subjected to uniaxial stresses in the [100], [110], and [111] directions is investigated. In the case of uniaxial stress in the [100] direction, the Oxygen Diffusion in 4YSZ and 8YSZ is facilitated in the tensile direction and deteriorated in the compressive direction without changing the total Diffusion property, which could be caused by the elastic recovery force. For 14YSZ, however, the Oxygen Diffusion remains unchanged regardless of the stress, probably due to high yttria concentration. In the case of tensile stress in the [110] and [111] directions, the Oxygen Diffusion is also increased in the tensile direction, which could be attributed to the improvement of the Oxygen Diffusion in the direction caused by the stress component in the direction.
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Oxygen Diffusion in yttria-stabilized zirconia subjected to uniaxial stress
Solid State Ionics, 2010Co-Authors: Wakako Araki, Yoshio AraiAbstract:In the present study, the Oxygen Diffusion in the yttria-stabilized zirconia was investigated under various stress conditions by means of the molecular dynamics simulation. With the uniaxial tensile stress, the Oxygen ions preferentially migrate in the tensile direction and hardly in the other vertical direction without changing the total Diffusion property. On the other hand, the uniaxial compressive stress deteriorates the Oxygen Diffusion in the compressive direction, which has the highest activation energy. These effects are clearly observed with the stress above 1 GPa and could be attributed to the elastic strain energy. For the case of the hydrostatic stress, the dilation by the tension increases the total Oxygen Diffusion whereas the shrinkage by the compression deteriorates it, which can be considered as the accumulative effect of the uniaxial stress in each direction. The present result indicates that the ionic conductivity of the yttria-stabilized zirconia could be enhanced by applying directional stresses.
Wakako Araki - One of the best experts on this subject based on the ideXlab platform.
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Optimum strain state for Oxygen Diffusion in yttria-stabilised zirconia
Solid State Ionics, 2011Co-Authors: Wakako Araki, Yoshio AraiAbstract:Abstract The strain effect of the Oxygen Diffusion in the yttria-stabilised zirconia in the present study was investigated by means of a molecular dynamics simulation. The simulation was conducted for various parameters such as the strain, temperature, yttria concentration, and potential parameter, and in addition, the biaxial and hydrostatic cases were considered. For a uniaxial strain, the Oxygen Diffusion was enhanced in the tensile direction whereas it was hindered in the compressive direction. The maximum improvement was achieved for a smaller strain at a lower temperature and also with a lower yttria concentration. For the biaxial and hydrostatic strains, the total Diffusion coefficient was enhanced simply as a result of the enhancement when using the uniaxial strain in each direction. The detailed deformation analysis reveals that the optimum strain state for the highest Oxygen Diffusion in the tensile direction can be obtained when the Oxygen ion is largely displaced in the fluorite lattice structure.
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Oxygen Diffusion in Yttria-Stabilized Zirconia Subjected to Mechanical Stress
Defect and Diffusion Forum, 2011Co-Authors: Wakako Araki, Yoshio AraiAbstract:The Oxygen Diffusion in 4, 8, and 14 mol%-yttria-stabilized zirconia subjected to uniaxial stresses in the [100], [110], and [111] directions is investigated. In the case of uniaxial stress in the [100] direction, the Oxygen Diffusion in 4YSZ and 8YSZ is facilitated in the tensile direction and deteriorated in the compressive direction without changing the total Diffusion property, which could be caused by the elastic recovery force. For 14YSZ, however, the Oxygen Diffusion remains unchanged regardless of the stress, probably due to high yttria concentration. In the case of tensile stress in the [110] and [111] directions, the Oxygen Diffusion is also increased in the tensile direction, which could be attributed to the improvement of the Oxygen Diffusion in the direction caused by the stress component in the direction.
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Oxygen Diffusion in yttria-stabilized zirconia subjected to uniaxial stress
Solid State Ionics, 2010Co-Authors: Wakako Araki, Yoshio AraiAbstract:In the present study, the Oxygen Diffusion in the yttria-stabilized zirconia was investigated under various stress conditions by means of the molecular dynamics simulation. With the uniaxial tensile stress, the Oxygen ions preferentially migrate in the tensile direction and hardly in the other vertical direction without changing the total Diffusion property. On the other hand, the uniaxial compressive stress deteriorates the Oxygen Diffusion in the compressive direction, which has the highest activation energy. These effects are clearly observed with the stress above 1 GPa and could be attributed to the elastic strain energy. For the case of the hydrostatic stress, the dilation by the tension increases the total Oxygen Diffusion whereas the shrinkage by the compression deteriorates it, which can be considered as the accumulative effect of the uniaxial stress in each direction. The present result indicates that the ionic conductivity of the yttria-stabilized zirconia could be enhanced by applying directional stresses.
James R. Durrant - One of the best experts on this subject based on the ideXlab platform.
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Correction: Oxygen Diffusion dynamics in organic semiconductor films
Journal of Materials Chemistry C, 2018Co-Authors: Safa Shoaee, James R. DurrantAbstract:Correction for ‘Oxygen Diffusion dynamics in organic semiconductor films’ by Safa Shoaee et al., J. Mater. Chem. C, 2015, 3, 10079–10084.
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Oxygen Diffusion dynamics in organic semiconductor films
Journal of Materials Chemistry C, 2015Co-Authors: Safa Shoaee, James R. DurrantAbstract:Transient absorption spectroscopy is commonly used to probe the yield and kinetics of excited states of materials. We present a transient absorption spectroscopic assay of Oxygen Diffusion in a series of solution-processed polymer films. The films were partially encapsulated with an epoxy/glass top barrier as a simple model system for organic photovoltaic and light emitting devices with metal top contacts. The results presented herein show that this spectroscopic approach can be a versatile and quantitative in situ assay of local Oxygen concentrations in such organic semiconductor films. With our current apparatus, the approach has a time resolution of 5 seconds, thereby enabling direct measurement of Oxygen Diffusion kinetics into a semiconductor film. The versatility of this approach suggests it could be widely applicable to measurement of Oxygen Diffusion into organic optoelectronic devices, including for example Oxygen Diffusion through encapsulation and barrier layers. Employing this approach, we demonstrate significant differences in Oxygen Diffusion kinetics between different semiconducting polymers. We furthermore demonstrate the impact of an additional getter (ZnO) and light exposure upon the local Oxygen concentration, providing new insights into the role of Oxygen Diffusion kinetics in determining the environmental stability of organic semiconductors.
V. D. Sokolovskii - One of the best experts on this subject based on the ideXlab platform.
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Oxygen Diffusion at surface reduction in catalysts for selective oxidation
Catalysis Letters, 1993Co-Authors: O. Yu. Ovsitser, V. D. SokolovskiiAbstract:The coefficient of Oxygen Diffusion and the activation energy for Diffusion have been measured for the series of oxide catalysts of selective oxidation of organic compounds (Sm-Mg-O, Sm-O; V-P-O, Sn-Sb-O, Sn-Bi-O, Fe-Sb-O, Bi-Sb-O). The rates of Oxygen Diffusion under catalytic conditions have been compared with the reaction rates. For all studied systems (except Sm-O and Sm-Mg-O) at optimal operative temperatures the maximum rate of Oxygen Diffusion is sufficient to carry out the reactions of selective oxidation through rapid Oxygen Diffusion in the surface layers.
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Role of Oxygen Diffusion in catalysts for selective oxidation
Reaction Kinetics & Catalysis Letters, 1992Co-Authors: V. D. Sokolovskii, O. Yu. OvsitserAbstract:The effective coefficients of Oxygen Diffusion for the series of oxide catalysts for the selective oxidation of organic compound (V−Mo−O, Bi−Mo−O, Ga−Sb−O, Mg−O) have been measured. Diffusion coefficients in different catalysts defined at optimal operation temperatures for these catalysts were found to be close. The possibility of using oxide systems as catalysts for selective oxidation is determined by their ability to achieve sufficiently large Oxygen Diffusion coefficients at the reaction temperature.
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Study of Oxygen Diffusion in MgO in the process of surface reduction
Catalysis Letters, 1991Co-Authors: O. Yu. Ovsitser, K. S. Guljaev, V. D. SokolovskiiAbstract:We have defined the coefficient of Oxygen Diffusion in MgO (Sspec = 55 m2/g) at 750 ° and 780 °C, the activation energy for Diffusion by measuring Oxygen Diffusion rates at different degrees of surface reduction. The method used for defining the Oxygen Diffusion rate is based on the increase in the rate of oxide catalyst reduction (CO or H2) after keeping the sample in vacuum.
Robin W. Grimes - One of the best experts on this subject based on the ideXlab platform.
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Effect of A-site cation disorder on Oxygen Diffusion in perovskite-type Ba0.5Sr0.5Co1−xFexO2.5
Journal of Materials Chemistry, 2013Co-Authors: Hiromasa Shiiba, Clare L. Bishop, M.j.d. Rushton, Masayuki Nogami, John A. Kilner, Masanobu Nakayama, Robin W. GrimesAbstract:Molecular dynamics simulations of the effect of A-site cation disorder on Oxygen Diffusion in (Ba0.5Sr0.5)CoO2.5, (Ba0.5Sr0.5)FeO2.5 and (Ba0.5Sr0.5)Co0.8Fe0.2O2.5 were conducted to understand the Oxygen Diffusion mechanism. The Diffusion coefficients of Oxygen were strongly dependent upon the degree of A-site Ba/Sr cation ordering. The Oxygen Diffusion coefficient decreased and the Oxygen Diffusion activation energy increased with Ba/Sr cation ordering in the alternating (001) layers of the perovskite structure. The ordering of Ba/Sr cations also caused Oxygen/vacancy ordering. In particular, vacancy location in the Oxygen layers parallel to the Ba-rich layers significantly increased Oxygen diffusivity in BSCF-related materials.
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effect of a site cation disorder on Oxygen Diffusion in perovskite type ba0 5sr0 5co1 xfexo2 5
Journal of Materials Chemistry, 2013Co-Authors: Hiromasa Shiiba, Clare L. Bishop, M.j.d. Rushton, Masayuki Nogami, John A. Kilner, Masanobu Nakayama, Robin W. GrimesAbstract:Molecular dynamics simulations of the effect of A-site cation disorder on Oxygen Diffusion in (Ba0.5Sr0.5)CoO2.5, (Ba0.5Sr0.5)FeO2.5 and (Ba0.5Sr0.5)Co0.8Fe0.2O2.5 were conducted to understand the Oxygen Diffusion mechanism. The Diffusion coefficients of Oxygen were strongly dependent upon the degree of A-site Ba/Sr cation ordering. The Oxygen Diffusion coefficient decreased and the Oxygen Diffusion activation energy increased with Ba/Sr cation ordering in the alternating (001) layers of the perovskite structure. The ordering of Ba/Sr cations also caused Oxygen/vacancy ordering. In particular, vacancy location in the Oxygen layers parallel to the Ba-rich layers significantly increased Oxygen diffusivity in BSCF-related materials.
