• 제목/요약/키워드: pinning effect

검색결과 134건 처리시간 0.018초

Pinning potential of a perpendicular magnetic domain wall due to a point defect

  • Song, Kyungmi;Lee, Kyung-Jin
    • 한국자기학회:학술대회 개요집
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    • 한국자기학회 2013년도 자성 및 자성재료 국제학술대회
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    • pp.139-140
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    • 2013
  • We investigate effect of a point defect on the pinning potential for a perpendicular magnetic domain wall based on the NEB method. We find that this method can give a reasonable value for the pinning potential and allows us to study the effect of various geometrical and magnetic properties on the pinning potential. In the presentation, we will discuss the effect of Ku and wire width on the pinning potential in detail.

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Effect of double pinning mechanism in BSO-added GdBa2Cu3O7-x thin films

  • Oh, J.Y.;Jeon, H.K.;Lee, J.M.;Kang, W.N.;Kang, B.
    • 한국초전도ㆍ저온공학회논문지
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    • 제19권3호
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    • pp.13-17
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    • 2017
  • We investigated the effect of self-assembled BSO nano-defects as pinning centers in BSO-added GdBCO films when the thicknesses of films were varied. 3.5 vol. % BSO-added GdBCO films with varying thicknesses from 200 nm to 1000 nm were deposited on $SrTiO_3$ (STO) substrate by using pulsed laser deposition (PLD) process. For the films with thicknesses of 400 nm and 600 nm, 'anomaly shoulders' in $J_c-H$ characteristic curves were observed near the matching field. The anomaly shoulders appeared in the field dependence of $J_c$ may be attributed to the existence of double pinning mechanisms in thin films. The fit to the pinning force density as a function of reduced field h ($H/H_{irr}$) using the Dew-Hughes' scaling law shows that both the 400 nm- and the 600 nm-thick films have double pinning mechanisms while the other films have a single pinning mechanism. These results indicate that the self-assembled property of BSO result in different role as pinning centers with different thickness.

산화은을 첨가한 초전도체의 자기 속박효과 (Magnetic Pinning Effect of High Tc Superconductor)

  • 이상헌
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제55권4호
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    • pp.209-212
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    • 2006
  • The electromagnetic effect observed in a BiSrCaCuO superconductor was studied. The electromagnetic properties of a $Ag_2O$ doped BiSrCaCuO superconductor and an undoped superconductor were evaluated to investigate the contribution of the pinning effect. It was confirmed experimentally that a large amount of magnetic flux was trapped in the $Ag_2O$ doped BiSrCaCuO than that in the undoped one, indicating that the pinning centers of magnetic flux are related closely to the occurrence mechanism of magnetic phenomena. It was considered that by adding $Ag_2O$, the area where normal conduction takes place increases and the magnetic flux penetrating through the sample increases. It also was considered that $Ag_2O$ acts to increase pinning centers of magnetic flux.

BiPbSrCaCuO 초전도 벌크의 Magnetic Suspension (Magnetic Suspension Effect of BiPbSrCaCuO Superconducting Bulk)

  • 이상헌
    • 한국전기전자재료학회논문지
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    • 제17권5호
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    • pp.545-551
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    • 2004
  • Magnetic suspension effect has been studied by using superconductor of BiPbSrCaCuO ceramics containing Ag$_2$O. Magnetic flux measurements of a toroidal magnet revealed a concave shaped field distribution with a null field along the axis of the torus at the point where the field reversed. The suspension effect was observed only for the Ag$_2$O doped and field cooled sample which is attributed to the enhanced flux pinning due to the field cooled condition. It has been cleared that Ag$_2$O acts as pinning center which plays an important role to the magnetic suspension effect. Magnetic repulsive force which affects a superconductor located in magnetic flux from toroidal magnet has been investigated. It has been concluded that the magnetic suspension effect arises from the interaction between the pinning effect and the diamagnetic effect.

Electromagnetic Properties of Bi System Superconductor for Magnetic Levitation Car Maglev

  • Lee, Sang-Heon
    • Journal of Electrical Engineering and Technology
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    • 제2권1호
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    • pp.102-105
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    • 2007
  • Effects of $Ag_2O$ doping on the electromagnetic properties in the BiSrCaCuO superconductors. The electromagnetic properties of the $Ag_2O$ doped and undoped BiSrCaCuO superconductor were evaluated to investigate the contribution of the pinning centers to the magnetic effect. It was confirmed experimentally that a large amount of magnetic flux was trapped in the $Ag_2O$ doped sample than that in the undoped one, indicating that the pinning centers of magnetic flux are related closely to the occurrence of the magnetic effect. It is considered that the area where normal conduction takes place increases by adding $Ag_2O$ and the magnetic flux penetrating through the sample increases. The results suggested that Ag acts to increase the pinning centers of the magnetic flux, contributing to the occurrence of the electromagnetic properties.

The flux pinning properties of BaSnO3-added GdBa2Cu3O7-δ films with varying growth conditions

  • Lee, J.K.;Oh, J.Y.;Lee, J.M.;Kang, W.N.;Kang, B.
    • 한국초전도ㆍ저온공학회논문지
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    • 제19권3호
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    • pp.18-22
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    • 2017
  • Addition of $BaSnO_3$ (BSO) to $GdBa_2Cu_3O_{7-{\delta}}$ (GdBCO) is reported to enhance the flux pinning property of GdBCO thick films. To investigate the effect of growth condition on the pinning properties, 700 nm-thick BSO-added GdBCO films deposited with varying temperatures and growth rates were prepared by using a pulsed laser deposition method. As the deposition temperature increases, the critical current density and the pinning force density show an improved field dependence up to $750^{\circ}C$ due to the increase in the formation of the a-axis growth and the BSO nanostructures. The films deposited at higher temperatures show degraded surfaces and as a result, degraded pinning behaviors. For the change in growth rate, the critical current density and the pinning force increase as the repetition rate increase at low magnetic fields, but this behavior is reversed in high magnetic fields. These results indicate that the film growth conditions significantly affect the formation of BSO nanostructures and the pinning properties of BSO-added GdBCO films.

Bi계 초전도제의 자기부양효과 (Magnetic Suspension Effect of BiPbSrCaCuO Superconductor)

  • 이상헌
    • 한국전기전자재료학회논문지
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    • 제15권6호
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    • pp.535-538
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    • 2002
  • Suspension effect has been studied by using superconductor of BiPbSrCaCuO ceramics containing $Ag_2()$. It has been clear that $Ag_2()$ acts as pinning center which plays an important role to the suspension effect. Magnetic repulsive force which affects a superconductor located in magnetic flux from toroidal magnet, has been investigated. It has been concluded that the suspension effect arises from the interaction between the pinning effect and the diamagnetic effect.

산화물 초전도체의 자기효과 (Magnetic Suspension Effect of Oxide Superconductor)

  • 이상헌;이성갑;이영희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 춘계학술대회 논문집 반도체 재료 센서 박막재료 전자세라믹스
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    • pp.199-202
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    • 2004
  • Suspension effect has been studied by using superconductor of BiPbSrCaCuO ceramics containing $Ag_2O$. It has been c1eared that $Ag_2O$ acts as pinning center which plays an important role to the suspension effect. Magnetic repulsive force which affects a superconductor located in magnetic flux from toroidal magnet has been investigated. It has been concluded that the suspension effect arises from the interaction between the pinning effect and the diamagnetic effect.

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Bi계 초전도체의 Magnetic Suspension (Magnetic Suspension Effect of BiPbSrCaCuO Superconductor)

  • 이상헌
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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    • pp.101-103
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    • 2001
  • Suspension effect has been studied by using superconductor of BiPbSrCaCuO ceramics containing $Ag_{2}O$ It has been cleared that $Ag_{2}O$ acts as pinning center which plays an important role to the suspension effect. Magnetic repulsive force which affects a superconductor located in magnetic flux from toroidal magnet has been investigated. It has been concluded that the suspension effect arises from the interaction between the pinning effect and the diamagnetic effect.

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BiPbSrCaCuO 초전도체의 Fishing 효과 (Fishing Effect of BiPbSrCaCuO Superconductor)

  • 이상헌
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 춘계학술대회 논문집 방전 플라즈마 유기절연재료 초전도 자성체연구회
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    • pp.177-179
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    • 2004
  • Suspension effect has been studied by using superconductor of BiPbSrCaCuO ceramics containing $Ag_2O$. It has been cleared that $Ag_2O$ acts as pinning center which plays an important role to the suspension effect. Magnetic repulsive force which affects a superconductor located in magnetic flux from toroidal magnet has been investigated. It has been concluded that the suspension effect arises from the interaction between the pinning effect and the diamagnetic effect.

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