• The Korean Journal of Ceramics
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• 제2권4호
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• pp.221-225
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• 1996

In diamond synthesis by metal film growth method under high pressure and high temperature, the nucleation and growth of diamond was observed dependent on the carbon source variation from graphite powder to the heat treated powders of lamp black carbon. At the low driving force condition near equilibrium pressure and temperature line, nucleation of diamond did not occur but growth of seed diamond appeared in the synthesis from lamp black carbon while both nucleation and growth of diamond took place in the synthesis from graphite. Growth morphology change of diamond occurred from cubo-octahedron to octahedron in the synthesis from graphite but very irregular growth of seed diamond occurred in the synthesis from lamp block carbon. Lamp black carbon transformed to recrystallized graphite first and very nucleation of diamond was observed on the recrystallized graphite surface. Growth morphology of diamond on the recrystallized graphite was clear cubo-octahedron even at higher pressure departure condition from equilibrium pressure and temperature line.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1885-1890
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• 2008

3-D heterogeneous nucleation was simulated by classical molecular dynamics (MD), where the Lennard-Jones (LJ) gas and solid cluster-seed molecules have argon and aluminum properties, respectively. There are three shapes of cluster-seeds, cube, rod, and sphere, and three classes of masses and the simulation took place under nine supersaturation ratios, making a total of 81 calculations. Results show that the dimension of the cluster-seed highly affects the rates of cluster development. In order to analyze heterogeneous nucleation above and below the critical supersaturation ratio, growth rate and liquefaction rate were separately defined to supplement the investigation. Design of experiments (DOE) was used for analysis which displayed that the shape and mass of the cluster-seed are prominent for the growth rate, while the supersaturation ratio is most significant followed by the mass for liquefaction rate. The significance of the supersaturation ratio for overall liquefaction suggests that thermal diffusion is more dominant than mass interactions for this system.

• 한국결정성장학회지
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• 제29권6호
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• pp.239-244
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• 2019

수소 분위기 열처리 및 수소 플라즈마 처리의 두 가지 수소화 표면개질을통해 나노다이아몬드 seed 입자의 분산 향상 및 평탄한 초미세 나노결정질 다이아몬드 박막증착을 위한 핵형성 밀도 향상을 확보하였다. 수소화 처리 이후 나노다이아몬드 입자 표면의 탄소-산소 및 산소-수소 결합기가 탄소-수소 결합기로 전환되는 화학적 표면개질이 진행되었고 Zeta 전위가 증가하였다. 분산도 향상에 따라 나노다이아몬드 응집체 크기가 현저하게 감소하였고 핵형성 밀도는 크게 증가하였다. 600℃, 수소분위기에서 열처리 이후 나노다이아몬드 평균 입자 크기가 3.5 ㎛에서 34.5 nm로 크게 감소하였고, seeding 된 Si 기판 표면에서 ~3.9 × 10¹¹ nuclei/㎠의 매우 높은 핵형성 밀도를 확보하였다.

• 한국결정성장학회지
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• 제23권6호
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• pp.291-295
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• 2013

산화 및 수소 분위기 열처리를 통한 화학적 표면 개질로 나노다이아몬드 seed 입자의 응집성 완화 및 초미세나노결정질 다이아몬드 (UNCD) 박막 증착을 위한 핵형성 밀도 향상을 확보하였다. 열처리에 의해 나노다이아몬드 seed 입자표면 작용기가 개질되었고, 제타 전위도 증가하였다. 또한, 응집체 평균 크기가 약 $2{\mu}m$에서 ~55 nm로 크게 감소하였다. $600^{\circ}C$, 수소 열처리된 seed 입자로 seeding 한 Si 기판으로부터 열처리하지 않은 seed 입자에 비해 현저하게 향상된 ${\sim}2.7{\times}10^{11}cm^{-2}$의 매우 높은 핵형성 밀도를 확보하였다.

• 한국세라믹학회지
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• 제32권5호
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• pp.587-593
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• 1995

Abnomal grain growth behavior of BaTiO3 ceramics was investigated with addition of seed grains. It was foudn that the nucleation rate of abnormal grain was constant and growth of abnormal grain was linearly increased with sitnering time, regardless of amount of seed grains. These facts were also confirmed by fitting of the volume fraction of abnormal grain vs. sintering time using Avrami type equation (n=4). It was suggested that seed grains did not change the nucleation rate or growth mechanism of abnormal grain but increase the number of abnormal grains at initial stage of sintering and then it led to fine microstructure of BaTiO3 ceramics.

• 한국재료학회지
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• 제11권9호
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• pp.802-809
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• 2001

Electroplating is an attractive alternative deposition method for copper with the need for a conformal and conductive seed layer In addition, the Cu seed layer should be highly pure so as not to compromise the effective resistivity of the filled copper interconnect structure. This seed layer requires low electrical resistivity, low levels of impurities, smooth interface, good adhesion to the barrier metal and low thickness concurrent with coherence for ensuring void-free fill. The electrical conductivity of the surface plays an important role in formation of initial Cu nuclei, Cu nucleation is much easier on the substrate with higher electrical conductivities. It is also known that the nucleation processes of Cu are very sensitive to surface condition. In this study, copper seed layers deposited by magnetron sputtering onto a tantalum nitride barrier layer were used for electroplating copper in the forward pulsed mode. Prior to electroplating a copper film, the Cu seed layer was cleaned by plasma H$_2$ and $N_2$. In the plasma treatment exposure tome was varied from 1 to 20 min and plasma power from 20 to 140W. Effects of plasma pretreatment to Cu seed/Tantalum nitride (TaN)/borophosphosilicate glass (BPSG) samples on electroplating of copper (Cu) films were investigated.

• 한국세라믹학회지
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• 제36권10호
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• pp.1048-1055
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• 1999

• 한국결정성장학회지
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• 제12권4호
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• pp.190-195
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• 2002

NaX seed결정(10~20 $\mu$m)을 $3.5Na_2$O : $Al_2O $: $2.1SiO_2$ : $1000H_2$O 용액에 0.5~2.0g 첨가한 후 연속결정화법으로 50 $\mu$m의 균일한 결정을 성장시켰다. 연속결정화법에 의한 결정성장을 시험하기 위하여, 모액을 7일, 5일, 3일, 2일과 1일 간격으로 공급하였다. Seed 첨가의 결과는 첨가하지 않은 용액과 비교하여 보다 균일하고 큰 결정들을 얻었다. 합성용액에 seed의 첨가는 반응물과 물리적인 접촉 면적을 초래하여 합성 겔의 핵성장 없이 seed 결정의 결정성장을 확인할 수 있다.

• 한국세라믹학회지
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• 제42권9호
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• pp.599-601
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• 2005

The coarsening process of two different $BaTiO_3$ single crystal seeds, one with a (111) double twin and the other without it, was investigated. Due to the presence of Twin Plane Reentrant Edge (TPRE), the coarsening rate of the twinned seed crystal was significantly higher than that without a twin. For the coarsening by the 2-dimensional nucleation and lateral growth, the energy barrier for nucleation at the TPRE was analyzed to be about a half compared with that at the terrace planes.

• Progress in Superconductivity
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• 제9권1호
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• pp.115-118
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• 2007

This study investigated the effects of different kinds of seed crystals with miscut angles and pretreatment on the characteristics of a RE-123 superconductor processed by a top-seeded melt-growth (TSMG) method. When the seed crystal was heat-treated in an oxygen atmosphere, the surface structure was cleaned removing hydroxide. When the seed crystal had a miscut angle, in addition, the surface structure showed a well defined hill-and-valley structure after heat-treatment. A better microstructure, with a well-distributed small RE-123 phase, was obtained using a high miscut angle after heat-treatment in an oxygen atmosphere. As a result of the microstructure improvement, the magnetic characteristics also improved. The experimental result can be explained by reduction of nucleation activation energy.