• 한국자기학회:학술대회 개요집
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• 한국자기학회 2002년도 춘계연구발표회 논문개요집
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• pp.152-153
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• 2002

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2016년도 자성 및 자성재료 국제학술대회
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• pp.33-33
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• 2016

• Journal of Magnetics
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• 제19권3호
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• pp.227-231
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• 2014

We fabricated textured polycrystalline $CoFe_2O_4$ thin films on $Pt(111)/TiO_2/SiO_2/Si$ substrate through a sol-gel method. We varied the thickness of the films, by using precursor solutions with different concentrations of 0.1, 0.2, and 0.3 M, and by depositing 5, 8, or 10 layers on the substrate by spin-coating. X-ray diffraction spectra indicated that when the precursor concentration of the solution was higher than 0.1 M, the spin-coated films were preferentially oriented in the <111> direction. Inspection of the surface morphology by scanning electron microscopy revealed that $CoFe_2O_4$ thin films prepared with 0.2 M solution and 5-time spin-coatings had smoother surface, as compared to the other conditions. Each coating had an average thickness of about 50 nm. The magnetic properties measured by vibrating sample magnetometer showed magnetic anisotropy, as evidenced from the difference in the in-plane and out-of-plane hysteresis loops, which we attributed to the textured orientation of the $CoFe_2O_4$ thin films.

• Bulletin of the Korean Chemical Society
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• 제15권12호
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• pp.1042-1045
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• 1994

A thin film of silver ferricyanide (Ag$_3$Fe(CN)$_6$) on a platinum or gold substrates can be reduced electrochemically to the salt of silver ferrocyanide in potassium nitrate solution. The color of these films are orange and these films are shown to be electrochromic. The voltammogram is shown the asymmetry of the oxidation compared to the reduction wave under various supporting electrolytes. The standard heterogeneous electron-transfer rate for these films and bare Pt electrode were 0.49 ${\times}$ l0$^{-2}$ and 1.30 ${\times}$ l0$^{-2}$ cm/s, respectively, obtained using a rotating disc electrode. Rough D$_0$ values, evaluated from the Levich equation, for Fe(CN)$_6^{3-/4-}$ at both SF thin film and a bare Pt disc electrode were shown as 1.2l ${\times}$ l0-6 and 0.94 ${\times}$ l0$^{-6}$ cm$^2$/s, respectively. The conductivities, as determined from the slops of the i-V curves for a ca. 1 mm sample for dried SF potassium rich and deficient bulk samples pressed between graphite electrodes, were 9.34 ${\times}$ l0$^{-9}$ and 5.80 ${\times}$ l0$^{-9}$ (${\Omega}$${\cdot}$cm)$^{-1}$, respectively.

• 한국세라믹학회지
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• 제35권3호
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• pp.294-302
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• 1998

$Pb_{1+x}$($Fe_{0.5}$$Nb_{0.5}$)$O_3$ films have been synthesized on Pt/Ti/$SiO_2$/Si substrates using rfmagnetron sputtering Concentration of Fe and Nb in the deposited films was adjusted to near stoichiometry through the control of target composition, Films deposited with adjusted to near stoichiometry showed better electrical properties such as dielectic and leakage characteristics. Crystallinity and dielectric constant increased with increasing excess PbO upto 9 mol% This study also showed that dielectric constant and leakage current characteristics improved by optimum content of $O_2$ flow during deposition.

• Journal of Magnetics
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• 제9권4호
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• pp.121-124
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• 2004

NiO thickness dependences of perpendicular magnetic anisotropy (PMA) in the $NiO/[CoFe/Pt]_5$ multilayers for exchange biasing and $[CoFe/Pt]_4/Pt/[CoFe/Pt]_4$ for interlayer exchange coupling were investigated. Perpendicular magnetization curve was obtained by out-of-plane extraordinary Hall measurement. Magnetic force microscopy (MFM) has been used for the investigation of magnetic domains on thin films. We confirmed that the interlayer exchange coupling (IEC) as a function of NiO thickness at room temperature existed with a period of two monolayers.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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• pp.1829-1831
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• 2005

Ferroelectric $Bi_{3.25}Nd_{0.75}Ti_3O_{12}$(BNdT) thin films were proposed for capacitor of FeRAM. The BNdT thin films were grown on Pt/Ti $SiO_2/P-Si(100)$ substrates by the RF magnetron sputtering deposition. The dielectric properties of the BNdT were investigated by varying post-annealing temperatures. Increasing post-annealing temperature, the (117) peak was increased. An increase of rod type grains of BNdT films with increasing post-annealing temperature was observed by the Field Emission Scanning Electron Microscopy(FE-SEM). The dielectric constant and dielectric loss of the BNdT thin films with post-annealing temperature of $700^{\circ}C$ were 418 and 0.37, respectively.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2008년도 Asian Magnetics Conference
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• pp.12.2-12.2
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• 2008

• 한국진공학회지
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• 제7권1호
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• pp.17-23
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• 1998

RF magnetron co-sputtering법으로 PFN[$Pb(Fe_{0.5}Nb_{0.5}O_3(PFN)$]박막을 제조한 후 급속 열처리(rapid thermal annealing, RTA)하여 XRD(s-ray diffractometer)를 통한 박막의 상변 태 및 전기적 특성에 대하여 연구하였다. $SiO_2$/Si, ITO/glass, 및 Pt/Ti/$SiO_2$/Si기판에 PFN 박막을 증착시켰다. 기판의 변화에 따른 증착된 PFN박막의 조성변화는 관찰할 수 없었다. ITO/glass기판을 사용한 경우와 $SiO_2$/Si기판을 사용하여 증착시킨 PFN박막의 결정구조를 분석한 결과 ITO/glass기판에 증착한 시편이 perovskite상으로의 결정화가 더욱 우세하였다. 이는$SiO_2$기판의 경우 Pb의 확산에 의해 결정화가 잘 되지 못하기 때문이다. Pt/Ti/$SiO_2$/Si 기판 위에 증착시킨 PFN박막의 경우 perovskite상과 pyrochlore상이 공존하였다. Perovskite 상으로의 상변태에 대한 중요한 변수로는 열처리 온도와 Pb의 함량인 것이 확인되었으며, Pb의 함량이 화학양론적 조성비에 비해 5-10%정도 과량일수록 perovskite상으로의 상변태 온도가 낮아지고 상전이 정도가 향상되는 것으로 나타났으며, 급속 열처리 후 XRD를 이용 한 결정성 분석결과를 통해 결정한 perovskite상으로의 상전이 최저온도는 $500^{\circ}C$였다. Pb/(Fe+Nb)의 조성비가 1.17인 경우의 박막을 질소 분위기 하에서 $600^{\circ}C$로 30초간 급속열 처리 하였을 때 낮은 누설 전류 값과 1kHz에서 88의 유전 상수 값, 2.0$\mu$C/$\textrm{cm}^2$의 잔류 분극 값과 144kV/cm의 항전계 값을 얻었다.

• Transactions on Electrical and Electronic Materials
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• 제11권5호
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• pp.212-215
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• 2010

$BiFeO_3/Pb(Zr_{0.95}Ti_{0.05})O_3$ (BFO/PZT) heterolayered thin films were fabricated by the spin coating method on a Pt/Ti/$SiO_2$/Si substrate using metal alkoxide solutions. The coating and heating procedure was repeated 6 times to form the heterolayered films. The thickness of the BFO/PZT films after one cycle of drying/sintering is about 30-40 nm. All BFO/PZT films show a void free uniform grain structure without the presence of rosette structures. It can be assumed that the crystal growth of the upper BFO layers can be influenced by the lower PZT layers. As the number of coatings increased, the dielectric constant increased, so that the value for the 6-layer film was 1360 at 1 KHz.