• Journal of the Korean Magnetics Society
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• v.6 no.5
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• pp.317-322
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• 1996

Thin films of Fe-Zr-N were fabricated by rf magnetron reactive sputtering method. The saturation magnetization and coercivity as functions of annealing temperature and partial pressure of nitrogen gas, effective permeability at high frequencies, and thermal stability were investigated. Magnetic softness was exhibited in the composition range of $Fe_{72-78}Zr_{7-10}N_{15-18}$ which was boundary between polycrystalline and amorphous structure. These films exhibited magnetic softness with saturation magentic flux density of 1.55 T and effective permeability of about 3000 at 1 MHz. These films also exhibited thermal stability by sustaining effective permeability of 2500 or above as the temperature was raised to $550^{\circ}C$. It is asswned that good magnetic softness is obtained because grain growth of $\alpha-Fe$ is prohibited due to the precipitation of ZrN nanocrystals. The grain sizes of $\alpha-Fe$ films were $40~50\AA$ and the grain sizes of ZrN nanocrystals were $10~15\AA$.

• 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.

• Journal of the Korean Magnetics Society
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• v.3 no.3
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• pp.215-220
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• 1993

Microstructural dependence of magnetic property of RF/DC sputtered $Co_{69.0}Ni_{18.5}Cr_{12.5}/Cr$ double layer thin film was studied. Grain size was found to be decreased with substrate temperature in the range of $100-200^{\circ}C$ and Cr underlayer thickness(from $500\;{\AA}-2000\;{\AA}$). The peaks (200) and (1120) of X-ray diffraction patterns were evidently grown with the substrate temperature for the Cr underlayer and magnetic layer, respectively. The CoNiCr magnetic layer was found to be well epitaxialy grown on Cr underlayer, and subsequently the coercivity was enhanced.

• Korean Journal of Materials Research
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• v.9 no.8
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• pp.831-836
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• 1999

Magnetic properties of (Fe(sub)1-xCo(sub)x)(sub)89Zr11 amorphous films fabricated by RF sputtering method have been investigated as a function of Co content x. By means of two step field annealing at 190~20$0^{\circ}C$ for 10 minutes in the magnetic field of 130 Oe, the film with x=0.4 among the samples shows the superior soft magnetic properties in spite of showing the high magnetostriction. For example, the obtained properties of coercivity and differential permeability measured in an exciting field of 10 mOe at the frequency of 8.7 MHz are 0.25 Oe and 280, respectively. It is confirmed that such behavior is due to the variation of magnetic anisotropies caused by a optimal compressive stress within the film.

• Korean Journal of Materials Research
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• v.10 no.10
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• pp.709-714
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• 2000

SAW 소자에 응용 가능한 자성박막재의 개발을 목적으로 RF 스퍼터링법으로 증착한 (Fe(sub)0.6Co(sub)0.4)(sub)89Zr(sub)11/Fe(sub)1-xCo(sub)x)Zr(sub)11(x=0, 0.6, 0.9)<원문잠조> 비정질 다층박막의 자기특성을 조사하였다. 수직자기장중열처리를 행하였을 때 상온에서 비자성 Fe(sub)89Zr(sub)11 층의 삽입에서만 다층박막화의 효과가 나타났다. 일 예로 (Fe(sub)0.6Co(sub)0.4)(sub)89Zr(sub)11(30${\AA}$)/Fe(sub)89-Zr(sub)11(40${\AA}$)<원문참조> 박막시편에 1kHz, 50 mOe의 여기자기장으로 평가된 최대 미분투자율${\mu}$(sub)d.max는 단층막의 750에서 1650으로 2배 이상 증가, 구동 바이어스자기장 Hw는 20 Oe에서 6Oe로 3배 이하로 감소하는 양호한 특성이 얻어졌다. 그러나 다른 중용 특성인 자왜는 34% 정도 감소하는 것으로 추정되었다.

• Journal of the Korean Magnetics Society
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• v.12 no.5
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• pp.184-188
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• 2002

The Cu/Ni/Cu(002)/Si(100) films which have perpendicular magnetic anisotropy were deposited by e-beam evaporation methods. From the reflection high energy electron diffraction pattern, the films were confirmed to be grown epitaxially on silicon. After 2X lots ions/$\textrm{cm}^2$ C+ irradiation, magnetic easy-axis was changed from surface normal to in-plane as shown in the hysteresis loop of magneto-optical Kerr effects. It became manifest from analysis of X-ray reflectivity and grazing incident X-ray diffraction that even though interface between top Cu layer and Ni layer became rougher, the contrast of Cu and Ni's electron density became manifest after ion irradiation. In addition, the strain after deposition of the films was relaxed after ion irradiation. Strain relaxation related with change of magnetic properties and mechanism of intermixed layer's formation was explained by thermo-chemical driving force due to elastic and inelastic collision of ions.

• Journal of the Korean Magnetics Society
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• v.14 no.2
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• pp.59-64
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• 2004

We investigated the soft magnetic properties of nanocrystalline Fe-Al-O film as etching the oxide film with ion beam etching method. It is thought that the grain size of Fe-Al-O film increases as the thickness decreases. The coercivity and squareness increase with decreasing thickness. The surface curvature of Am images increases when the etching experiment proceeds. This phenomena could be due to the grain growth which occurs during sputtering. This grain growth could be assisted by the the plasma energy during sputtering. Therefore proper thickness should be searched to acquire the good soft magnetic properties for the nanocrystalline film material. Good soft magnetic properties of Fe-Al-O film was acquired at the thickness of more than 900 nm.

• Proceedings of the Korean Magnestics Society Conference
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• 2012.11a
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• pp.146-148
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• 2012

미크론 자성비드 검출용 바이오센서에 활용하는 GMR-SV 박막을 이온빔 스퍼터링 증착법으로 glass/Ta(5.8 nm)/NiFe(5 nm)/Cu(t nm)/NiFe(3 nm)/FeMn(12 nm)/Ta(5.8 nm)의 구조를 갖도록 증착하였다. 비자성체 Cu의 두께가 3.0 nm에서 2.2 nm까지 얇아질수록 교환결합력은 증가하였으며 자기저항비는 다소 낮았다. 비자성체의 두께가 얇으면 반강자성체의 층간 교환작용이 강자성체의 고정층 뿐만 아니라 자유층의 스핀배열에도 영향을 주고 있음을 확인할 수 있었다. 또한 리소그래피 공정 과정을 거쳐 GMR-SV 소자를 제작하여 미트론 자기비드를 검출하였다. 여기서 자기비드를 떨어뜨리기 전과 후의 자기저항비, 교환결합력, 보자력은 각각 0.9%, 3 Oe, 2 Oe의 값을 나타내었다. 이것으로 미크론단위의 바이오센서로서 활용할 수 있는 가능성을 보여주었다.

• Journal of the Korean Magnetics Society
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• v.19 no.2
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• pp.52-56
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• 2009

Interlayer coupling field, coercivity, magnetoresitance ratio, and magnetic sensitivity depending on the thickness of free CoFe layer for the CoFe/Cu/CoFe/IrMn multilayer are investigated. In case of CoFe layer of $30\;{\AA}$ thickness for the CoFe(t)/Cu($25\;{\AA}$)/CoFe($60\;{\AA}$)/IrMn($80\;{\AA}$) multilayer with ferromagnet/non-magnet/ferromagnet structure induced by IrMn layer, the lowest coercivity and the highest magnetic sensitivity, which is contained soft magnetic property, are observed. On the other side, in case of CoFe layer of $90\;{\AA}$ thickness, there are the highest coercivity and the lowest magnetic sensitivity. The fabricated CoFe($30\;{\AA}$)/Cu($25\;{\AA}$)/CoFe($60\;{\AA}$)]/IrMn($80\;{\AA}$) spin valve device with $2{\times}8{\mu}m^2$ patterning size are measured by two probe method, which is selected the sensing current as the longitudinal direction and the easy axis as the transversal direction. The measuring magntoresistance ratio and magnetic sensitivity of GMR-SV device having the soft magnetic property are 3.0% and 0.3%/Oe, respectively.

• Journal of the Korean Magnetics Society
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• v.3 no.4
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• pp.320-324
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• 1993

The effect of sputtering conditions on magnetic properties of CoCrMo/Cr magnetic thin film was investigated. Substrate temperature were controlled from R. T to $250^{\circ}C$. The thickness changes of Cr underlayer and CoCrMo magnetic layer were in the range of $1000-2500\AA$ and $300-800\AA$, respectively. Grain size was found to be decreased with increasing magnetic layer thickness(from $500\AA$ to $800\AA$). CoCrMo magnetic layer microstructure showed relatively small dependence on Cr underlayer thickness, substrate temperature. Coercivity increased with increasing Cr underlayer, magnetic layer thickness and substrate temperature. CoCrMo/Cr thin film showed a coercivity of 880 Oe in $700\AA$ magnetic layer thickness and $1000\AA$ Cr underalyer thickness.