• Journal of Magnetics
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• v.16 no.2
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• pp.92-96
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• 2011

This study investigated theoretically the properties of the spin transfer torque acting on a ferromagnet in a ferromagnet-normal metal-antiferromagnet junction. Earlier work showed that the angular dependence of the spin transfer torque can be a wavy-type if the junction satisfies a special symmetry. This paper reports a simple model analysis that allows a derivation of the wavy angular dependence without taking advantage of the symmetry. This result suggests that the wavy angular dependence can appear even when the symmetry is broken. As an illustration, the angular dependence was calculated as a function of the degree of the compensation at the normal metal-antiferromagnet interface. The implications of the result for the current-induced magnetization precession are discussed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.699-702
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• 2002

A DC current sensor is disclosed in which two pairs of saturable cores are provided so as enclose a conductor carrying a direct current to be measured. On each of the saturable cores, a bias winding, a feedback winding and an output winding are wound. Circuit for detection of an asymmetry in the magnetization current, generated by a reference alternating voltage, in a signal-conditioner. The reference alternating voltage is fed to the respective series circuits such that no resultant induction current is induced in the modulating current. The voltages over the resistor form input signals for two peak value detectors, the strength of the output signal of which represents the degree of asymmetry of magnetization current. This paper describes the development a DC current sensor and its signal-conditioner.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.320-322
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• 2003

This paper describes a current differential relaying algorithm for a three-phase transformer considering the nonlinear magnetization characteristics of the core. The iron-loss current is obtained from the calculated induced voltage and the core-loss resistance. The magnetizing current is calculated from the estimated core flux and the magnetization curve. The proposed algorithm uses the modified differential current, which is obtained by subtracting the iron-loss current and the magnetizing current from the conventional differential current. The various test results show that the algorithm can discriminate internal fault from magnetic inrush, overexcitation and an external fault.

• Korean Journal of Metals and Materials
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• v.50 no.3
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• pp.248-255
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• 2012

AlN thin films containing various amounts of Co, AlN-Co, and Al-Co alloy particles were prepared using a two-facing-target type dc reactive sputtering (TFTS) system. The as-deposited films exhibited the variable nature expected from an AlN-rich phase, and an amorphous-like phase, depending on the Co content in the films. Specific favorable microstructures were prepared by optimizing annealing conditions. Those microstructures and their magnetic properties and resistivity were investigated. As-deposited films showed very small saturation magnetization and an amorphous-like structure. However, when annealed, the as-deposited amorphous-like phase decomposes into phases of AlN, Co and Al-Co. These annealing induced changes in the microstructure improve the magnetization and resistivity of the films. Further improvement of soft magnetic properties could lead to the material being used for high density magnetic recording head material.

• Proceedings of the Korean Magnestics Society Conference
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• 2006.06a
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• pp.82-83
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• 2006

• Proceedings of the Korean Magnestics Society Conference
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• 2007.05a
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• pp.234.2-234.2
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• 2007

• Proceedings of the Korean Magnestics Society Conference
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• 2007.05a
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• pp.118.2-118.2
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• 2007

• Proceedings of the Korean Magnestics Society Conference
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• 2012.11a
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• pp.103-103
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• 2012

• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.214.2-214.2
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• 2008

• Progress in Superconductivity and Cryogenics
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• v.21 no.1
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• pp.1-5
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• 2019

The pulsed field magnetization of the short-circuited soldered double pancake coil made of stabilized commercial high-Tc superconductor (HTS) tape is experimentally studied. The evolution of the shielding current induced by the pulsed field and the trapped field after the pulsed magnetization was measured at 77 K. It is shown that the trapped field in the coil is close to the value reached in the field cooling process and reduces weakly at 5-fold increasing of pulsed field amplitude. The current relaxation at t~2 ms after the pulse is defined by the current sharing between the tape's copper coating and the $YBa_2Cu_3O_{7-d}$ layer. In the intermediate time scale (1 s < t < 100 s) the flux creep in HTS layer dominates. At t > 100 s the current's relaxation is defined by the resistance of soldered joint between tapes.