The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
Hyun M. Jang - One of the best experts on this subject based on the ideXlab platform.
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co metal clustering as the origin of ferromagnetism in co doped zno thin films
Applied Physics Letters, 2004Co-Authors: Jung H Park, Hyun M. JangAbstract:The origin of ferromagnetism in ZnO-based systems was investigated using Co-doped ZnO thin films as prototypical examples of II–VI-based diluted magnetic semiconductors. In spite of the atomic-scale dissolution of Co ions in wurtzite ZnO, both the magnetization-Temperature Curve and the magnetization-field Curve demonstrated that Zn1−xCoxO thin films were paramagnetic for x⩽0.12. On the other hand, Zn1−xCoxO films with x greater than 0.12 were characterized by the Co-metal clustering and apparently showed room-Temperature ferromagnetism. The discrepancy between the zero-field cooling and the field cooling Curves further indicates that Co-doped ZnO films (for x>0.12) are superparamagnetic and the observed ferromagnetism originates from the nanometer-sized Co clusters.
H Kurt - One of the best experts on this subject based on the ideXlab platform.
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conductance enhancement due to interface magnons in electron beam evaporated mgo magnetic tunnel junctions with cofeb free layer deposited at different pressure
Journal of Applied Physics, 2014Co-Authors: P Guo, Jiafeng Feng, H Kurt, Junyang Chen, Hongyuan Wei, J M D Coey, Xiufeng HanAbstract:Electron-beam evaporated MgO-based magnetic tunnel junctions have been fabricated with the CoFeB free layer deposited at Ar pressure from 1 to 4 mTorr, and their tunneling process has been studied as a function of Temperature and bias voltage. By changing the growth pressure, the junction dynamic conductance dI/dV, inelastic electron tunneling spectrum d2I/dV2, and tunneling magnetoresistance vary with Temperature. Moreover, the low-energy magnon cutoff energy EC derived from the conductance versus Temperature Curve agrees with interface magnon energy obtained directly from the inelastic electron tunneling spectrum, which demonstrates that interface magnons are involved in the electron tunneling process, opening an additional conductance channel and thus enhancing the total conductance.
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conductance enhancement due to interface magnons in electron beam evaporated mgo magnetic tunnel junctions with cofeb free layer deposited at different pressure
Journal of Applied Physics, 2014Co-Authors: Jiafeng Feng, H Kurt, Junyang Chen, D L Li, Guoqiang Yu, J M D CoeyAbstract:Electron-beam evaporated MgO-based magnetic tunnel junctions have been fabricated with the CoFeB free layer deposited at Ar pressure from 1 to 4 mTorr, and their tunneling process has been studied as a function of Temperature and bias voltage. By changing the growth pressure, the junction dynamic conductance dI/dV, inelastic electron tunneling spectrum d2I/dV2, and tunneling magnetoresistance vary with Temperature. Moreover, the low-energy magnon cutoff energy EC derived from the conductance versus Temperature Curve agrees with interface magnon energy obtained directly from the inelastic electron tunneling spectrum, which demonstrates that interface magnons are involved in the electron tunneling process, opening an additional conductance channel and thus enhancing the total conductance.
Jiafeng Feng - One of the best experts on this subject based on the ideXlab platform.
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conductance enhancement due to interface magnons in electron beam evaporated mgo magnetic tunnel junctions with cofeb free layer deposited at different pressure
Journal of Applied Physics, 2014Co-Authors: P Guo, Jiafeng Feng, H Kurt, Junyang Chen, Hongyuan Wei, J M D Coey, Xiufeng HanAbstract:Electron-beam evaporated MgO-based magnetic tunnel junctions have been fabricated with the CoFeB free layer deposited at Ar pressure from 1 to 4 mTorr, and their tunneling process has been studied as a function of Temperature and bias voltage. By changing the growth pressure, the junction dynamic conductance dI/dV, inelastic electron tunneling spectrum d2I/dV2, and tunneling magnetoresistance vary with Temperature. Moreover, the low-energy magnon cutoff energy EC derived from the conductance versus Temperature Curve agrees with interface magnon energy obtained directly from the inelastic electron tunneling spectrum, which demonstrates that interface magnons are involved in the electron tunneling process, opening an additional conductance channel and thus enhancing the total conductance.
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conductance enhancement due to interface magnons in electron beam evaporated mgo magnetic tunnel junctions with cofeb free layer deposited at different pressure
Journal of Applied Physics, 2014Co-Authors: Jiafeng Feng, H Kurt, Junyang Chen, D L Li, Guoqiang Yu, J M D CoeyAbstract:Electron-beam evaporated MgO-based magnetic tunnel junctions have been fabricated with the CoFeB free layer deposited at Ar pressure from 1 to 4 mTorr, and their tunneling process has been studied as a function of Temperature and bias voltage. By changing the growth pressure, the junction dynamic conductance dI/dV, inelastic electron tunneling spectrum d2I/dV2, and tunneling magnetoresistance vary with Temperature. Moreover, the low-energy magnon cutoff energy EC derived from the conductance versus Temperature Curve agrees with interface magnon energy obtained directly from the inelastic electron tunneling spectrum, which demonstrates that interface magnons are involved in the electron tunneling process, opening an additional conductance channel and thus enhancing the total conductance.
Huaizhu Li - One of the best experts on this subject based on the ideXlab platform.
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the internal and external factor on coal ash slag viscosity at high Temperatures part 3 effect of cao on the pattern of viscosity Temperature Curves of slag
Fuel, 2016Co-Authors: Lingxue Kong, Wen Li, Xiaoming Li, Huaizhu LiAbstract:Abstract Limestone is widely used in entrained flow gasifiers to improve slag viscosity properties, while viscosity–Temperature Curve of slag is typical of a crystalline slag when CaO content is above a certain level, of which the viscosity sharply increases when the Temperature is lowered below Temperature of critical viscosity ( T CV ). Experiments were conducted on selected slags at about 5 wt% Fe 2 O 3 level to investigate effect of CaO on the pattern of viscosity–Temperature Curve (PVTC) of slag. The results showed that the higher CaO content at which the viscosity of slag exhibited the behavior of a crystalline slag increased as silica/alumina ratio (S/A) of slag increased. PVTC of slag was essentially depended on the increase of solid amount with decreasing Temperature. Although solid amount at high Temperatures was lowered due to addition of CaCO 3 , its average increase rate (Rs) increased with increasing CaO content. When anorthite and melilite were the dominant solid formed in slag, the viscosity of slag will exhibite the behavior of a crystalline slag once Rs exceeded 0.250 wt%/°C. However, effect of CaO content on Rs diminished with increasing S/A when Rs was less than 0.250 wt%/°C. Rs is able to be used as the indication for using limestone as flux for slag tapping.
Chiungchang Huang - One of the best experts on this subject based on the ideXlab platform.
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effect of hydrophobic chain length of surfactants on enthalpy entropy compensation of micellization
Journal of Physical Chemistry B, 1998Co-Authors: Lijen Chen, Chiungchang HuangAbstract:It is well-known that there exists a minimum critical micelle concentration (cmc) in the cmc−Temperature Curve. It is found that the Temperature of minimum cmc, Tmin, for both nonionic and ionic surfactants increases as the hydrophobicity of surfactants decreases. The Temperature dependence of cmc is used to calculate the enthalpies and entropies of micelle formation for six different homologous series of surfactants. The enthalpy−entropy compensation plot exhibits an excellent linearity. It is found that all the compensation lines for surfactants in a homologous series are parallel to one another and the intercept of these compensation lines is a linear function of the hydrophobic chain length of surfactants.
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Temperature dependence of critical micelle concentration of polyoxyethylenated non ionic surfactants
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 1998Co-Authors: Lijen Chen, Chiungchang Huang, Enming ChenAbstract:Abstract The critical micelle concentrations (CMCs) of an n-dodecyl polyoxyethylene glycol monoether (C12H25O(C2H4O)jH) with three different oxyethlyene chain length (j=4, 6 and 8) are experimentally determined over the Temperature ranging from 10°C to 80°C using the Wihelmy plate technique. It is found that there exists a minimum CMC in the CMC-Temperature Curve. The Temperature of the minimum CMC for three systems is around 50°C. The enthalpy and entropy of micelle formation are evaluated. The correlation of enthalpy and entropy of micelle formation exhibits an excellent linearity, and the compensation Temperature is 321 K, dramatically larger than previous findings for non-ionic surfactants in aqueous solutions.
