• Journal of the Korean Magnetics Society
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• v.21 no.4
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• pp.132-135
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• 2011

The exchange bias field ($H_{EX}$) and the coercivity ($H_C$) variation and change depending on the thickness of intermediately super-soft magnetic NiFeCuMo layer with different thickness of the bottom NiFe layer were investigated. The $H_{EX}$ of triple pinned NiFe(4 nm)/NiFeCuMo($t_{NiFeCuMo}$= 1 nm)/NiFe(4 nm)/FeMn multilayer has the maximum value more less than one of single pinned NiFe(8 nm)/FeMn layer. If NiFeCuMo layer is inserted each into between the pinned and free NiFe layers, we can be used as GMR-SV device for a bio-sensor that has improved magnetic sensitivity.

• Electrical & Electronic Materials
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• v.10 no.9
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• pp.938-944
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• 1997

Cu-Ni thin film strain gauges for diaphragm-type pressure sensors were developed. Thin films of Cu-Ni alloys of various compositions were deposited onto glass and stainless steel substrates by RF magnetron sputtering. The effects of composition substrate temperature Ar partial pressure and aging on the electrical properties of Cu-Ni film strain gauges in the thickness range 500~2000$\AA$ are discussed. The maximum resistivity(95.6 $\mu$$\Omega$cm) is obtained from 53wt%Cu-47wt%Ni films while the temperature coefficient of resistance(TCR) becomes minimum(25.6ppm/$^{\circ}C$). The gauge factor is about 1.9.

• Journal of the Korean Vacuum Society
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• v.4 no.1
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• pp.67-76
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• 1995

자기저항헤드용 Ni-Fe-Co/Cu/Ni-Fe-Co/Fe-Mn 다층박막에서 자기적 성질과 전기적 성질에 관하여 조사하였다. 저 포화자계에서 고 자기저항을 나타내는 스핀 밸브형 다층박막을 제작하기 위하여 Borond이 도핑된 p-type Si(100)기판위에 Ni-Fe-Co 단층박막과 Si/Ni-Fe-Co/Cu/Ni-FeCo, Si/Ni-Fe-Co/Fe-Mn 구조의 다층막을 제작하여 자기적 특성을 조사하였다. Ni-Fe-Co 단층박막의 자기적 특성은 고정된 아르곤 분압에서 박막의 두께 등에 의존성이 있는 것으로 나타났다. 또한 Si/Ni-Fe-Co($70AA$)/Fe-Mn 구조에서 Ni-Fe-Co와 Fe-Mn 계면에서의 두 자성층의 이방성 차이에 의해서 발생되어지는 교환자기이방성이 존재하였으며, 교환자기이방성자계값은 Fe-Mn 두께가 $150\AA$일 때 가장 큰 값을 나타내었다. Ni-Fe-Co texture와 교환자기이방성자계값은 Fe-Mn 두께가 $150\AA$일 때 가장 큰 값을 나타내었다. Ni-Fe-Co texture와 교환자기이방성자계값의 의존성을 알아보기 위하여 Ti, Cu를 바닥층으로 사용하였다. Ti을 바닥층으로 사용하였을 경우, 교환자기이방성자계값은 23.5 Oe 정도의 가장 큰 값을 나타내었다. XRD 분석결과, Ti 바닥층이 Cu 바닥층이나, 바닥층이 없는 경우와 비교하여 성막된 Ni-Fe-Co 자성층의 강한 fcc(111) texture를 형성하는 것으로 나타났다. 각각의 단층박막과 다층박막에서의 자기적 특성을 측정한 후, Si/Ti($50\AA$)/Ni-Fe-Co($70\AA$)/Cu($23\AA$)/Ni-Fe-Co($70\AA$)/Fe-Mn(150$\AA$)/Cu(50$\AA$)의 스핀밸브구조를 갖는 다층박막을 제작하였으며, 11 Oe의 낮은 포화자계값에서 4.1%의 고 자기저항값을 얻을 수 있었다.

• Journal of the Korean Magnetics Society
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• v.9 no.5
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• pp.251-255
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• 1999

NiFe(60 $\AA$)/Co(0$\AA$$\leq$x$\AA$$\leq$15$\AA$)/Cu(60$\AA$)/Co(30$\AA$) spin valve thin films were prepared on 4$^{\circ}$ tilt-cut Si(111) substrates with a 50 $\AA$ thick Cu underlayer without applying any external magnetic field during the deposition, and the effects of inserted ultrathin Co layer on magnetic anisotropy and GMR properties of the NiFe(60 $\AA$)/Cu(60$\AA$)/Co(30$\AA$) spin valves were investigated. As the ultrathin Co layer was inserted into the NiFe/Cu interface of the spin valves, GMR ratio was increased from about 1.5% to 3.5%, and the easy axis of NiFe(60 $\AA$) layer was rotated by 90$^{\circ}$. Accordingly, it was aligned along the same direction with the easy axis of Co(30 $\AA$)layer. Therefore, squared R-H curves was obtained in the spin valves, which is favorable properties for the digital GMR devices such as MRAM. In order to investigate the change of magnetic anisotropy of NiFe layer of the spin valves in more details,XRD measurement was performed using NiFe(500 $\AA$) and NiFe(500 $\AA$)/Co(10 $\AA$) thin films on the same templates. Strong (220) NiFe peak was observed in both films regardless of the inserted Co layer, so it was thought that the variation of magnetic anisotropy of NiFe layer is from the interface effect, the change of interface from NiFe/Cu to NiFe/Co, rather than the volume effect such as the change of magnetocrystalline effect.

• Journal of the Korean Magnetics Society
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• v.20 no.4
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• pp.129-133
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• 2010

Two-layered ferromagnetic alloy films (NiFe, CoFe) with a Conetic (NiFeCuMo) intermediately soft magnetic layer of different thickness were investigated to correlate the coercivity values and magnetization process with the strength of saturation field of hard axis. Thickness dependence of the $H_{EC}$ (coercivity of easy axis), $H_{HS}$ (saturation field of hard axis.), and X (susceptibility) of NiFe and NiFeCuMo thin films for the glass/Ta(5 nm)/[CoFe or NiFe(5 nm-t/2)]/NiFeCuMo(t = 0, 4, 6, 8, 10 nm)/[CoFe or NiFe(5 nm-t/2)]/Ta(5 nm) films prepared by the ion beam deposition method was measured. The magnetic properties $H_{EC}$, $H_{HS}$, and X of two-layered ferromagnetic CoFe, NiFe films with a NiFeCuMo intermediately super-soft magnetic layer were strongly depended on the thickness of NiFeCuMo layer. The value of the coercivity and magnetic susceptibility of the NiFeCuMo film decreased by 25% and doubled relative to that of the NiFe film.

• Journal of the Korean Magnetics Society
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• v.5 no.2
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• pp.109-111
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• 1995

We suggest the phenominological model to determine the mangetoelastic coupling coefficient in Cu/Ni/Cu thin films by considering effective anisotropy energy with magnetic film thicknesses. This indirect determination can be applied other single crystalline systems.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2003.11a
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• pp.265-269
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• 2003

Sn(또는 SnAg)/Ni(P)와 Sn/Cu 계의 열사이클동안 형성되는 금속간화합물에 의해 유기되는 응력의 변화를 in-situ로 관찰하였다. Sn(또는 SnAg)/Ni(11.7P) 박막은 계면반응으로 인해 $Ni_3P$와 $Ni_3Sn_4$ 상이 형성되고 이때 인장응력이 발생하였으며, 한편, Sn(또는 SnAg)/Ni(3P) 박막의 계면반응에 의해서는 동일한 $Ni_3P$와 $Ni_3Sn_4$ 상이 형성됨에도 불구하고 압축응력이 발생하였다. SmAg를 사용할 때 형성되는 $Ag_3Sn$이 응력에 미치는 영향은 거의 없었다. Sn/Cu 박막의 경우는 계면반응 초기에는 인장응력이 발생하였고 어느 정도 이상 반응이 진전됨에 따라 압축응력이 발생하였고 최종적으로 $Cu_3Sn$ 상이 형성되었다. 초기의 인장응력은 계면에서 원자들의 intermixing 베 의한 것이고 압축응력은 Sn 방향으로 일방향 성장하는 금속간화합물 형성에 기인한다.

• Journal of the Korean Magnetics Society
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• v.3 no.4
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• pp.289-292
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• 1993

[Ni/Fe/Cu] and [Fe/Ni/Fe/Cu] multilayers were prepared with three gun rf-magnetron sputtering, and dependence of magnetoresistance on the Ni IFe thickness ratio was investigated. Vaccum annealing was tried to invetigated the effect of annealing. Oscillation of magnetoresistance on the Cu spacer thickness was dbserved in these two kinds of multilayers. When the thickness of Fe inserted into the Ni/Cu interface was about $3\;\AA$. the maximum value of magnetoresistance(13 %) could be observed. In a sample of $1~2\;\AA$ Fe thickness, saturation field decreased significantly, while magnetoresistace decreased slightly in comparison with the sample of $3\;\AA$ Fe. In ${[Cu(23\;\AA)/Fe(1\;\AA)/Ni(18\;\AA)/Fe(1\;\AA)]}_{20}/Fe(80\;\AA)/Si$, 6 % magnetoresistance with 100 Oe saturation field could be obtained. No appreciable change in magnetoresistance and saturation field could be observed by low temperature annealing. Formation of Ni-Fe alloy was not confinred.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.10 no.1
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• pp.36-41
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• 2000

We studied the exchange anisotropy of Ni-Fe/Co-Fe/Mn-Ir/Cu/buffer/Si multilayers using D.C magnetron sputtering technique. Generally, Ni-Fe/Mn-Ir/buffer(Cu)/Si multilayers cannot pin the ferromagnetic layer for the lower exchange biased field. We got $H_{ex}$ ex/ increased by two times, after using Cu/Ta as buffer layer to get larger grain size of Mn-Ir layer and inserting very thin Co-Fe layer between the Ni-Fe layer and the Mn-Ir layer to get improved grain-to-grain epitaxy relation at the interface between Ni-Fe layer and Mn-Ir layer. The variation of $H_{ex}$ by thickness of Mn-Ir layer in ferromagnete/Mn-Ir/buffer/Si multilayers is different to that in Mn-Ir/ferromagnete/buffer/Si multilayers, because the volume distribution of grain size of Mn-Ir layer and the exchange energy at the interface between the Mn-Ir and the ferromagnetic layers is different for stacking sequence.

• Journal of the Korean Magnetics Society
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• v.20 no.1
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• pp.8-12
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• 2010

The magnetostriction and stress of multilayer $NiFeCr/(Cu/Co_{90}Fe_{10}){\times}N/NiFeCr$ films were investigated. As the number of Cu $15{\AA}$/CoFe $15{\AA}$ bilayers was increased, the saturation magnetostriction decreased from $-5.6\times10^{-6}$ at 2 bilayers to $-8.5\times10^{-6}$ at 20 bilayers. A change of CoFe thickness from 10 to $20{\AA}$ caused a decrease in the magnitude of tensile stress from 980MPa to 590MPa as the number of Cu $15{\AA}$/CoFe $15{\AA}$ bilayers increased from 2 to 20. The maximum magnetostrictive anisotropy field that could be developed due to nonzero magnetostriction and stress is calculated to be 135.7 Oe when the number of Cu $15{\AA}$/CoFe $15{\AA}$ bilayers is 10.