• 한국자기학회지
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• 제12권3호
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• pp.94-98
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• 2002

20nm이하의 얇은 박막에서도 높은 보자력이 요구되는 Ti/CoCrPt 수직자기기록박막의 보자력 향상을 위해 Al, Cu, Ni, Cr, Ag, Mg, Fe, Co, Pd, Au, Pt, Mo, Hf등의 여러 하지층과 제조조건이 보자력에 미치는 영향을 조사하였다 이들 중 Ag과 Mg하지층은 Ti/CoCrPt박막의 보자력을 향상시켰으며 특히 2nm Ag 하지층을 사용할 경우 10nm CoCrPt 박막에서 2200 Oe의 높은 보자력을 보일뿐 아니라 $\alpha$값을 낮추는 효과가 있었다. 그러나 Ag를 하지층으로 사용하면 기대와는 달리 Ti(002)면의 우선배향 성장이 전혀 일어나지 않아 보자력 증대에 다른 기구가 작용하는 것으로 판단되었다. 그리고 표면의 거칠기가 큰 기판에서는 보자력뿐만 아니라 역자구생성자계도 감소하였다.

• 한국표면공학회지
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• 제35권1호
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• pp.33-38
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• 2002

CrN 박막이 펄스마그네트론증착법에 의하여 glass, Si(110), AISI 1040 steel 위에 증착되어졌다. 각 기판 위에 증착된 CrN 박막의 구조는 표면의 접촉특성 보다는 표면의 구조에 영향을 받는 것으로 판단되어 진다. 또한 grain의 크기는 기판에 관계없이 증착 시간이 증가함에 따라 증가한다. AISI 1040 steel 위에 증착된 CrN 박막의 grain 성장과 구조는 glass와 Si에 비하여 바이어스에 강하게 영향을 받는다. 이러한 결과는 glass 와 Si 보다도 금속이 높은 전기전도성을 가지고 있기 때문인 것으로 생각되어 진다.

• Metals and materials international
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• 제24권6호
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• pp.1262-1274
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• 2018

The inhibition of gravity segregation has been a long-standing challenge in fabrication and applications of homogeneous immiscible alloys. Therefore, the effect of rare-earth La on the gravity segregation of Al-Bi immiscible alloys was investigated to understand the homogenization mechanism. The results showed that the addition of La can completely suppress the gravity segregation. This is attributed to the nucleation of Bi-rich liquid phase on the in-situ produced $LaBi_2$ phase and the change of the shape of $LaBi_2@Bi$ droplets. In addition, a novel strategy is developed to prepare the homogeneous immiscible alloys through the addition of rare-earth elements. This strategy not only is applicable to other immiscible alloys, but also is conducive to finding more elements to suppress the gravity segregation. This study provided a useful reference for the fabrication of the homogeneous immiscible alloys.

• 전기화학회지
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• 제8권1호
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• pp.17-23
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• 2005

$Bi_2O_3$를 첨가한 8M KOH용액에서 다결정 Ag전극의 전기화학적인 거동과 생성된 산화물들의 미세조직 변화를 분석하였다. $Bi_2O_3$를 첨가한 8M KOH용액에서 Ag 산화물뿐만 아니라 새로운 Ag-Bi-O화합물들이 생성되는 것을 알 수 있었다. Ag(I) 산화물 생성 전위 영역에서는 $Ag_2O$ 이외에, Ag-Bi-O 화합물이 핵 생성과 3D성장 과정에 의해서 생성되고, Ag(II)산화물 생성 전위 영역에서는 AgO뿐만 아니라 새로운 Ag-Bi-O화합물들이 핵 생성과 3D성장 과정에 의해서 생성되었다. Ag(I) 산화물 생성 전위에서 두 가지 형상의 Ag(I) 산화물이 생성되는 것을 SEM 조직에 의해 관찰하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 D
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• pp.1535-1537
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• 1999

Photochemical defluorination and substitution of fluorocarbon-resin surfaces using a pulsed Nd:YAG laser(266 nm) and copper-sulfate$(CuSO_4)$ aqueous solution were discussed. Interface of copper nuclei and fluorocabon-resin was chemically bonded through oxygen which was photodissociated from water in copper-sulfate aqueous solution under the laser irradiation. The reaction mechanism for chemical surface modification is discussed on the basis of x-ray photoelectron spectroscopy and atomic force microscope analyses.

• Advances in nano research
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• 제1권4호
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• pp.211-218
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• 2013

A low-cost, green and reproducible citric acid assisted synthesis of nanocrystalline $Al_{0.5}Ag_{0.5}TiO_3$ (n-AAT) powder is reported. X-ray, FTIR, energy dispersive X-ray, transmission electron microscopy and scanning electron microscopy analyses are performed to ascertain the formation of n-AAT. X-ray diffraction data analysis indicated the formation of monoclinic structure. Spherical shaped particles having the sizes of 3-15 nm are found. The mechanism of nano-transformation for the soft-chemical synthesis of n-AAT has been explained using simple organic chemistry rules and nucleation and growth theory. Dielectric study revealed that AAT ceramic might be a suitable candidate for capacitor applications.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2014년도 제49회 KOSCO SYMPOSIUM 초록집
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• pp.133-134
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• 2014

The full transport equation approach for laminar non-premixed flame with detailed chemistry, soot and radiation has an advantage in accuracy and describing for emission pathway, but this approach requires the excessive computational cost especially for a higher-order hydrocarbon fuel flames. On the other hand, the standard flamelet model has an efficiency and accuracy for non-premixed flame, though this model is not suitable for simulating slow processor like soot and radiation in laminar non-premixed flame situation. To overcome this limitation, modified transient flamelet model is developed which coupled with two-equation soot model involved in soot formation and evolution mechanism such as nucleation, surface growth, oxidation and agglomeration.

• 한국세라믹학회지
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• 제24권5호
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• pp.461-469
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• 1987

Single crystals of Mn-Zn Ferrite were grown by slow cooling method using Na2B4O7 as flux agent. The effects of flux content and cooling rate on the types of crystals, and the relation between supersaturation and growth mechanism were studied. As a result, the types of grown crystals occurred as plate, hopper and octahedral crystals. The occurrence of these crystal types was dependent on flux content. The habit was found to correlate with the growth rate and supersaturation. The lateral growth of a dendritic crystal is related to the twin layer. The growth of crystals from borax melts mainly occurred by the layer-spreading growth following corner and edge nucleation caused by high supersaturation in the melt. Especially, the plate crystals were produced on top of the melts. The hopper and octahedral crystals occurred at lower supersaturation than the plate crystals.

• 한국염색가공학회지
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• 제15권4호
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• pp.57-64
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• 2003

Poly(ethylene-co-vinyl acetate)(EVA) microspheres were prepared by a thermally induced phase separation. The microsphere formation occurred by the nucleation and growth mechanism in the metastable region. The diluent used was toluene. The microsphere formation and growth was followed by the cloud point of the optical microscope measurement. The microsphere size distribution, which was obtained by SEM observation and particle size analyzer, became broader when the polymer concentration was higher, the content of vinyl acetate in EVA copolymer was higher, and the cooling rate of EVA copolymer solution was lower.

• 한국진공학회지
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• 제2권4호
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• pp.507-514
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• 1993

The solid state reaction of Mo/Si multilayer thin films produced by RF magnetron sputtering technique was examine dusing differential scanning calorimetry (DSC) and x-ray diffraction, and explained in view of two concepts, effective drivig force and effective heat of formation. In constant scanning rate DSC, there were two exothermic peks which corresponded to the formation of h-MoSi2 and t-MoSi2 , respectively. The activation energyfor theformation of h-MoSi2 was 1.5eV , and that of t-MoSi2 was 7.8eV. Nucleation wa stherate controlling mechanism for each of the silicide formation. Amorphous phase was not formed , which was consistent withtheprediction by the concept of effective driving force. h-MoSi2 the first crystalline phase, was considered to have lower interfacial free energy than t-MoSi2 and by increasing temperature it was transformed into more stable t-MoSi2.