• Korean Journal of Materials Research
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• v.11 no.5
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• pp.378-384
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• 2001

In this study, nanostructured Fe-Ce powder with grain size of 10nm was produced by MA (mechanical alloying) process and was consolidated by PECS (pulse electric current sintering) process for the fabrication of bulk nanostructured Fe-Co softmagnetic alloy. PECS process was performed at 700, 800, 900 and $^1000{\circ}C$ with holding time ranging from 0 to 15min. The effectiveness of PECS Process to Produce nanostructured bulk specimens was estimated. The optimal PECS process condition for nanostructured Fe-Co powders was found through observing the change of relative density and microstructure with sintering temperature and holding time. The magnetic properties of the sintered specimens were evaluated through the measurement of coercivity and saturation magnetization.

• Journal of the Korean Magnetics Society
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• v.11 no.5
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• pp.222-225
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• 2001

The planar type inductors have a good potential for the application of miniaturized low power DC-DC converters. For those high quality application, the reduction of coil loss and also magnetic films which have good high frequency properties are required. Fabricated inductor was consisted of FeTaN/Ti magnetic film and electroplated Cu coil thickness of 100$\mu\textrm{m}$ and $SiO_2$ as a insulating layer. The inductor was designed double rectangular spiral shape for magnetic field highly confining within the device. The measured value of inductance and resistance were 980 nH and 1.7 $\Omega$ at 1 MHz as operating frequency of device. The Q factor is 3.55 at 1 MHz.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1806-1808
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• 2000

MHz영역에서 사용 가능한 Fe계 연자성 재료를 초미세 결정립으로 제조하기 위해 $Fe_{93}Zr_{3}B_4$ 박막을 기본조성으로 하여 Fe와 비고용이며 약반자성인 Ag 원소를 0, 3, 4, 5, 6, 10 at.% 첨가시킨 $Fe_{93-x}Zr_{3}B_{4}Ag_{x}$ 박막을 DC 마그네트론 스퍼터링법으로 제조하였다. 그리고, 300-600$^{\circ}C$ 온도 범위에서 1시간동안 열처리한 후 강제공냉법으로 냉각한 후 XRD를 이용하여 열처리 온도 및 Ag 첨가량에 따른 결정상 동정을 조사하였다. Ag가 첨가되지 않은 $Fe_{93}Zr_{3}B_4$ 박막의 경우 $\alpha$-Fe의 (110) 피크만 관찰되었다. Ag가 첨가된 경우에는, Ag의 양이 증가함에 따라 $\alpha$-Fe 결정상의 형성이 억제되고, 비정질형태의 broad한 ${\alpha}-Fe_{(110)}$ 피크와 Ag피크가 관찰되었다. Ag가 첨가된 As-deposited 시편을 열처리 할 경우 박막의 비정질화로 주 peak인 $\alpha$-Fe 피크의 강도가 현저히 낮아지고 상대적으로 Ag peak가 두드러졌다. Ag의 양이 3a/o인 경우는 열처리온도 400$^{\circ}C$이상에서 박막의 결정화로 $\alpha$-Fe Peak가 나타나고 상대적으로 Ag 구성원소의 피크의 강도는 현저하게 낮아졌다 또한. Ag의 양 증가할수록 As-deposited 박막 내에 Ag 구성원소외 피크의 강도는 증가하여 $\alpha$-Fe와 Ag가 서로 비고용 상태로 서로 혼재되어 있었다.

• Journal of the Korean Magnetics Society
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• v.14 no.6
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• pp.236-239
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• 2004

We studied the specular spin valve (SSV) having the spin filter layer (SFL) in contact with the ultrathin free layer composed of Ta3/NiFe2/IrMn7/CoFel/(NOLl)/CoFe2/Cu1.8/CoFe( $t_{F}$)/Cu( $t_{SF}$ )/(NOL2)/Ta3.5 (in nm) by the magnetron sputtering system. For this antiferromagnetic I $r_{22}$M $n_{78}$-pinned spin filter specular spin valve (SFSSV) films, an optimal magnetoresistance (MR) ratio of 11.9% was obtained when both the free layer thickness ( $t_{F}$) and the SFL thickness ( $t_{SF}$ ) were 1.5 nm, and the MR ratio higher than 11% was maintained even when the $t_{F}$ was reduced to 1.0 nm. It was due to increase of specular electron by the nano-oxide layer (NOL) and of current shunting through the SFL. Moreover, the interlayer coupling field ( $H_{int}$) between free layer and pinned layer could be explained by considering the RKKY and magnetostatic coupling. The coercivity of the free layer ( $H_{cf}$ ) was significantly reduced as compared to the traditional spin valve (TSV), and was remained as low as 4 Oe when the $t_{F}$ varied from 1 nm to 4 urn. It was found that the SFL made it possible to reduce the free layer thickness and enhance the MR ratio without degrading the soft magnetic property of the free layer.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1240-1243
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• 2008

The tempering and magnetic annealing are used to improve the soft magnetic properties such as initial permeability coercivity and core loss of the KM35F alloy. The first heat treatmentis performed at the temperature less than the curie temperature of the KM35F alloy to remove the thermal stress for few hours in nitrogen atmosphere. The second stage heat treatment is performed the magnetic annealing at $500{\sim}800^{\circ}C$ for few hours in nitrogen atmosphere, and then quenching to room temperature in absence of oxygen. Finally, magnetic properties of the thermally treated KM35F alloy are investigated for application as a soft magnetic material of the ISO solenoid valve core and plunger.

• Proceedings of the Korean Magnestics Society Conference
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• 2003.06a
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• pp.30-31
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• 2003

• Proceedings of the Korean Magnestics Society Conference
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• 2000.05a
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• pp.132-133
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• 2000

• Proceedings of the Petrological Society of Korea Conference
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• 2004.05a
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• pp.85-87
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• 2004

• Journal of Dental Rehabilitation and Applied Science
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• v.31 no.4
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• pp.378-386
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• 2015

Overdenture has the advantage of improving the stability and retention of the denture but the abutment may be easily affected by caries or periodontal disease and the thin denture can be easily broken. The magnetic attachment overdenture has a high vertical retention but a low horizontal retention, thus, exerting a less disruptive force to the abutment or implant and shows less abrasion or damage compared to other mechanical retainers. Denture fractures in overdenture is caused by the thin denture base as the attachment is inserted, but it may also be caused by the difference in detrusion between soft tissue and hard tissue, and between an implant and a natural tooth. To compensate this shortcoming, a magnetic attachment with a silicone ball inserted in the magnet was developed as we report a successful case using this specific type of magnetic attachment overdenture.

• Journal of the Korean Electrochemical Society
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• v.8 no.3
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• pp.125-129
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• 2005

We have investigated the electrochemical factors affecting the magnetic properties of hard magnetic CoP nanowires and soft magnetic CoFe nanowires fabricated by ac electrodeposition into self-made AAO(anodic aluminum oxide) nano-templates. AAO template having nano scale pores of high aspect ratio has been prepared through 2-step anodizing of aluminum foil in sulfuric acid. Hard Magnetic properties of CoP nanowires were highly conditional on the applied ac potential which could be a decisive factor to make CoP nanowires made up of either pure hcp crystals or a mixture of hop crystals and fcc crystals. On the contrary to CoFe films, there was no anomalous codeposition in the electrodeposition of soft magnetic CoFe nanowires which exhibited their best saturation magnetization of 238 emu/g at the composition of $Co_{30}Fe_{70}$.