The Experts below are selected from a list of 5235 Experts worldwide ranked by ideXlab platform
Zhupei Shi - One of the best experts on this subject based on the ideXlab platform.
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Effect of lead Resistance on spin-dependent tunneling junction with ion-beam deposited AlN barrier
Journal of Magnetism and Magnetic Materials, 1999Co-Authors: Chih-huang Lai, Lien-chang Wang, Hua-ching Tong, Bill Crue, Zhupei ShiAbstract:Abstract Directly ion-beam deposited AlN films were used as insulating barriers for spin-dependent tunneling junctions, and the effect of the lead Resistance on the Measured Δ R / R was investigated. `Bow-tie’ junctions with AlN thicker than 15 A showed non-linear I – V characteristics with Δ R / R of 1.4%. Junctions with AlN films thinner than 12 A showed small `negative’ Resistance with Δ R / R of −14%. The finite-element analysis was used to simulate the current flow and the Measured Resistance of the `bow-tie’ structure with different Resistance ratios of the tunneling junction to the lead. The result of simulation shows when the ratio is smaller than 0.077, the Measured Resistance becomes negative, and Δ R / R is significantly enhanced by the lead effect.
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Effect of lead Resistance on spin-dependent tunneling junction with ion-beam deposited AlN barrier
Journal of Magnetism and Magnetic Materials, 1999Co-Authors: Chih-huang Lai, Lien-chang Wang, Hua-ching Tong, Bill Crue, Zhupei ShiAbstract:[[abstract]]Directly ion-beam deposited AlN films were used as insulating barriers for spin-dependent tunneling junctions, and the effect of the lead Resistance on the Measured Delta R/R was investigated. 'Bow-tie' junctions with AlN thicker than 15 Angstrom showed non-linear I-V characteristics with Delta R/R of 1.4%. Junctions with AlN films thinner than 12 Angstrom showed small 'negative' Resistance with Delta R/R of - 14%. The finite-element analysis was used to simulate the current flow and the Measured Resistance of the 'bow-tie' structure with different Resistance ratios of the tunneling junction to the lead. The result of simulation shows when the ratio is smaller than 0.077, the Measured Resistance becomes negative, and Delta R/R is significantly enhanced by the lead effect.[[fileno]]2020314010020[[department]]材料
Chih-huang Lai - One of the best experts on this subject based on the ideXlab platform.
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Effect of lead Resistance on spin-dependent tunneling junction with ion-beam deposited AlN barrier
Journal of Magnetism and Magnetic Materials, 1999Co-Authors: Chih-huang Lai, Lien-chang Wang, Hua-ching Tong, Bill Crue, Zhupei ShiAbstract:Abstract Directly ion-beam deposited AlN films were used as insulating barriers for spin-dependent tunneling junctions, and the effect of the lead Resistance on the Measured Δ R / R was investigated. `Bow-tie’ junctions with AlN thicker than 15 A showed non-linear I – V characteristics with Δ R / R of 1.4%. Junctions with AlN films thinner than 12 A showed small `negative’ Resistance with Δ R / R of −14%. The finite-element analysis was used to simulate the current flow and the Measured Resistance of the `bow-tie’ structure with different Resistance ratios of the tunneling junction to the lead. The result of simulation shows when the ratio is smaller than 0.077, the Measured Resistance becomes negative, and Δ R / R is significantly enhanced by the lead effect.
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Effect of lead Resistance on spin-dependent tunneling junction with ion-beam deposited AlN barrier
Journal of Magnetism and Magnetic Materials, 1999Co-Authors: Chih-huang Lai, Lien-chang Wang, Hua-ching Tong, Bill Crue, Zhupei ShiAbstract:[[abstract]]Directly ion-beam deposited AlN films were used as insulating barriers for spin-dependent tunneling junctions, and the effect of the lead Resistance on the Measured Delta R/R was investigated. 'Bow-tie' junctions with AlN thicker than 15 Angstrom showed non-linear I-V characteristics with Delta R/R of 1.4%. Junctions with AlN films thinner than 12 Angstrom showed small 'negative' Resistance with Delta R/R of - 14%. The finite-element analysis was used to simulate the current flow and the Measured Resistance of the 'bow-tie' structure with different Resistance ratios of the tunneling junction to the lead. The result of simulation shows when the ratio is smaller than 0.077, the Measured Resistance becomes negative, and Delta R/R is significantly enhanced by the lead effect.[[fileno]]2020314010020[[department]]材料
Alain Schuhl - One of the best experts on this subject based on the ideXlab platform.
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Current distribution effects in patterned non-linear magnetoresistive tunnel junctions
Journal of Magnetism and Magnetic Materials, 2000Co-Authors: François Montaigne, F. Nguyen Van Dau, Alain SchuhlAbstract:To be used in submicronic devices like magnetic memories, magnetic tunnel junctions require low Resistances. Four-probe measurements of such Resistances are often altered by non-uniformity of the current distribution in the junction. The Measured Resistance is decreased by localised preferential conduction and increased by voltage drop in the measure electrode. Competition between these two effects is investigated as a function of the geometry. The non-linear conduction of tunnel junctions amplifies dramatically these phenomena and can modify by more than 50% the Measured Resistance.
Toshimitsu Morizane - One of the best experts on this subject based on the ideXlab platform.
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Middle Frequency Transformer Investigation for Solid-State Transformer
2018 International Conference on Smart Grid (icSmartGrid), 2018Co-Authors: Noriyuki Kimura, Toshimitsu MorizaneAbstract:This paper investigates the middle frequency transformer for the solid-state transformer. It is expected to be used in the traffic and power system. One of the key technologies is the solid-state transformer. The 3kHz, 5kVA transformers with some different core materials are manufactured. Dependency of the loss in the transformer to frequency is investigated. Estimated equation from the Steinmetz equation and some results are shown. Copper loss is also considered by using the Measured Resistance at various frequencies. It is indicated that the copper loss is major in the medium frequency transformer.
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Application of Solid-State Transformer for HVDC Transmission from Offshore Windfarm
2018 7th International Conference on Renewable Energy Research and Applications (ICRERA), 2018Co-Authors: Noriyuki Kimura, Toshimitsu Morizane, Isao Iyoda, Kazushige Nakao, Tomoki YokoyamaAbstract:This paper investigates the solid state transformer applied for the HVDC transmission from the offshore windfarm. The 3kHz, 5kVA transformers with some different core materials are manufactured. Dependency of the loss in the transformer to frequency is investigated. From the measurement, hysteresis loss and eddy current loss are separately considered for the higher frequency loss estimation. Copper loss is also considered by using the Measured Resistance at various frequencies. In this investigation, the difference of the core materials does not affect the loss largely but the copper loss does.
Winston O. Soboyejo - One of the best experts on this subject based on the ideXlab platform.
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Discrete modeling of transformation toughening in heterogeneous materials
Mechanics of Materials, 2004Co-Authors: D. Zeng, Noriko Katsube, Winston O. SoboyejoAbstract:Abstract This paper presents a hybrid finite element approach to the discrete modeling of transformation toughening. As opposed to the continuum approach, detailed microstructural features, including individual particle size and distribution, are incorporated into the discrete model. Based on the energy balance, size dependent critical stresses required for transformation of the particles are evaluated. These are then utilized in the numerical modeling of transformation toughening and Resistance-curve behavior. Using an iterative procedure, the transformation zone height, distribution of the transformed particles, and crack-tip shielding due to transformation toughening are predicted as functions of crack growth. The results obtained from the numerical analyses are compared with Measured Resistance-curves obtained from experiments conducted on a model nickel aluminide composite reinforced with yttria-stabilized zirconia particles. The numerical predictions are shown to be in very good agreement with the Measured Resistance-curve when the actual particle distributions are modeled.