• Title/Summary/Keyword: Magnetic device

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Uniaxial Magnetic Anistotropy of a NiO-Spin Valve Device

  • Lee, Won-Hyung;Hwang, Do-Guwn;Lee, Sang-Suk
    • Journal of Magnetics
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    • v.14 no.1
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    • pp.18-22
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    • 2009
  • The shape anisotropy effect of a giant magnetoresistance-spin valves (GMR-SV) device with a glass/NiO/NiFe/CoFe/Cu/CoFe/NiFe layered structure for use in the detection of magnetic property of molecules within a cell was investigated. The patterned device was given uniaxial anisotropy during the sputtering deposition and vacuum post-annealing, which was performed at $200^{\circ}C$ under a 300 Oe magnetic field. The pattern size of the device, which was prepared through the photolithography process, was $2{\times}15\;{\mu}m^2$. The experimental results confirmed that the best design for a GMR-SV device to be used as a biosensor is to have both the axis sensing current and the easy axis of the pinned NiO/NiFe/CoFe triple layer oriented in the direction of the device's width, while the easy axis of the free CoFe/NiFe bilayer should be pointed along the long axis of the device.

Developing Wearable Joystick Device Using Magnetic Sensor (자기장 센서를 이용한 웨어러블 조이스틱 장치의 개발)

  • Yeo, Hee-Joo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.1
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    • pp.18-23
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    • 2021
  • There has been demand for many magnetic sensor applications, and to develop low-cost devices, it is critical to accurately understand the behavior of the magnetic field and the characteristics of magnetic sensors and target devices during initial development phase. The magnetic field has been known to have very complicated nonlinear data to calculate, so it has required expensive computing machines or research to accurately calculate the magnetic sensor values. However, this paper introduces a characteristic of a magnetic sensor called the giant magnetoresistance (GMR) and proposes simple and sufficient approaches to develop a wearable joystick device using a magnetic sensor. Particularly, this paper introduces the design factors for how to properly develop a low-cost wearable joystick device using magnetic sensors after carefully considering the mechanism of a real joystick and the characteristics of magnetic sensors. As a result, user test results are provided to show how users can operate this new wearable joystick device.

Influences of Magnetic Field on Injection Time of Ferrite Slurry (자기장이 페라이트 슬러리의 주입시간에 미치는 영향)

  • Im, Jong-In;Yook, Young-Jin;Lee, Young-Jin
    • Journal of the Korean Ceramic Society
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    • v.43 no.12 s.295
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    • pp.829-832
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    • 2006
  • In this study, the influence of the magnetic field on ferrite slurry's injection time during the slurry forming process was investigated. The evaluation system of the slurry's injection time under the strong magnetic field was designed with FEM and manufactured. Studied parameters were the applied magnetic field, the input pressure of the slurry, and the supplying tube materials. As the results, the injection time was increased with the external magnetic field strength and rapidly decreased with increasing the input pressure of the slurry. Also the injection time was decreased when the supplying tube was manufactured with the magnetic material having the higher magnetic permeability than the ferrite.

Effects of an External Magnetic Field on the Magnetic Properties of Sputtered Magnetic Thin Films (스퍼터링 중 외부자기장이 자성박막의 자기적 특성에 미치는 영향)

  • Ahn, Hyun Tae;Lim, Sang Ho;Jee, Kwang Koo;Han, Jun Hyun
    • Korean Journal of Metals and Materials
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    • v.49 no.6
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    • pp.505-513
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    • 2011
  • A magnetic device which enables the application of a strong and uniform magnetic field to thin film during sputtering was designed for controlling the magnetic anisotropy using a three dimensional finite element method, and the effects of the external magnetic field on the magnetic properties of sputtered thin films were investigated. Both the intensity and the uniformity of the magnetic flux density in the sputter zone (50 mm ${\times}$50 mm) was dependent on not only the shape and size of the magnet device but also the magnitude of stray fields from the magnet. For the magnet device in which the distance between two magnets or two pure iron bars was 80-90 mm, the magnetic flux density along the direction normal to the external magnetic field direction was minimum. The two row magnets increased the magnetic flux density and uniformity along the external magnetic field direction. An Fe thin film sputtered using the optimized magnet device showed a higher remanence ratio than that fabricated under no external magnetic field.

A Three-dimensional Magnetic Field Mapping System for Deflection Yoke of Cathode-Ray Tube

  • Park, K.H.;Yoon, M.;Kim, D.E.;Lee, S.M.;Joo, H.D.;Lee, S.D.;Yang, W.Y.
    • Journal of Information Display
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    • v.3 no.4
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    • pp.19-22
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    • 2002
  • In this paper, we introduce an efficient three-dimensional magnetic field mapping system for a Deflection Yoke (DY) in Cathode-Ray Tube (CRT). A three-axis Hall probe mounted in a small cylindrical bar and three-stepping motors placed in a non-magnetic frame were utilized for the mapping. Prior to the mapping starts, the inner contour of DY was measured by a laser sensor to make a look-up table for inner shape of DY. Three-axis magnetic fields are then digitized by a three-dimensional Hall probe. The results of the mapping can be transformed into various output formats such as multi pole harmonics of magnetic fields. Field shape in one, two and three- dimensional spaces can also be displayed. In this paper, we present the features of this mapping device and some analysis results.

Korean Institute of Electrical and Electronic Materials (방향성 규소강판에서 열화특성이 자기적 성질에 미치는 영향)

  • Kim, Hyung-Wook;Kim, In-Sung;Jeong, Soon-Jong;Min, Bok-Ki;Song, Jea-Sung
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.06a
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    • pp.245-246
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    • 2006
  • 방향성 규소강판을 tape-wound core 형태로 제작하여 $N_2$ gas 분위기에서 $760^{\circ}C$ 4 시간동안 열처리후 자기적 특성을 조사 하였다. 그 결과 1차, 2차 권선수가 85 turns 시료에서 보자력(Hc)과 포화자속밀도(Bs)는 최대값을 나타내었고, 보자력은 0.019Oe, 포화자속밀도는 1.92T 이었다. 현재 국내에서 생산되고 있는 방향성 규소강판의 자속밀도값 보다 더 우수한 값을 나타내었으며, 열화특성이 자기적 특성에 미치는 영향을 통해 고효율 방향성 규소강판 개발의 가능성을 확인하였다.

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Magnetic Characteristics of an InSb Hall Device of Multilayerd Structure (다충구조 InSb 홀소자의 제작과 특성)

  • 이우선;김상용;서용진;박진성;김창일
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.13 no.8
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    • pp.681-687
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    • 2000
  • Magnetic Characteristics of an InSb hall device of multilayered structures were investigated. For the measurement of electrical properties of the hall device InSb thin films fabricated with series and parallel multilayers wee evaporated. Hall coefficient hall mobility carrier density and hall voltage were measured as a function of the intensity of magnetic field. We found that the XRD analysis of InSb thin film showed good properties at 20$0^{\circ}C$ 60 minutes. Resistance of ohmic contact was increased linearly due to increasing current. Hall voltages at 0.01 T showed 5$\times$10$^{-4}$ [V] and $1.5\times$10$^{-3}$ [V]. Some of device fabrication technique and analysis of magnetic characteristics were discussed.

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Development of magnetic field measurement system for AMS cyclotron

  • Ho Namgoong;Hyojeong Choi;Mitra Ghergherehchi;Donghyup Ha;Mustafa Mumyapan;Jong-Seo Chai;Jongchul Lee;Hoseung Song
    • Nuclear Engineering and Technology
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    • v.55 no.8
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    • pp.3114-3120
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    • 2023
  • A high-accuracy magnetic field measurement device based on a cyclotron is being developed for accelerator mass spectrometry (AMS). In this study, a magnetic field measurement device consisting of a Hall probe sensor, piezo-motor, and step motor was developed to measure the magnetic field of the AMS cyclotron magnet. The Hall probe sensor was calibrated to achieve positional accuracy by using polar coordinates. The measurement results between the ratchet gear and piezo-motor, which are the instruments used for driving the measurement device, were analyzed. The measurement result of the device with a piezo-motor exhibits a difference of 5 Gauss (0.04%) as compared with the simulation result.

Monitoring Inductance Change to Quantitatively Analyze Magnetic Wear Debris in Lubricating Oil (인덕턴스 측정에 의한 윤활유 내 자성입자 정량적 평가)

  • Koo, HeeJo;Ahn, Hyo-Sok
    • Tribology and Lubricants
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    • v.32 no.6
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    • pp.189-194
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    • 2016
  • Wear debris in lubricating oil can be indicative of potential damage to mechanical parts in rotating and reciprocating machinery. Therefore, on-line or in-line monitoring of lubricating components in machinery is of great importance. This work presents a device based on inductive measurement of lubricating oil to detect magnetic wear particles in a tested volume. The circuit in the device consists of Maxwell Bridge and LVDT to measure inductance differences between pure and contaminated oil. The device detects the passage of ferrous particles by monitoring inductance change in a coil. The sensing principle is initially demonstrated at the microscale using a solenoid. The device is then tested using iron particles ranging from $50{\mu}m$ to $100{\mu}m$, which are often found in severely worn mechanical components. The test results show that the device is capable of detecting and distinguishing ferrous particles in lubricating oil. The design concept demonstrated here can be extended to an in-line monitoring device for real-time monitoring of ferrous debris particles. A simulation using the CST code is performed to better understand the inductive response in the presence of magnetic bodies in the oil. The CST simulation further verifies the effectiveness of inductance measurement for monitoring magnetic particles within a tube.