• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2004년도 춘계총회 및 연구발표회 초록집
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• pp.37.2-37.2
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• 2004

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2003년도 춘계총회 및 연구발표회 초록집
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• pp.96.2-96
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• 2003

• 한국반도체및디스플레이장비학회:학술대회논문집
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• 한국반도체및디스플레이장비학회 2003년도 추계학술대회 발표 논문집
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• pp.109-116
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• 2003

Amorphous GaN Quantum dots(a-GaN QDs) with particle diameters less than bohr radius(~11nm) were successfully fabricated at room temperature by a laser ablation of high densified GaN target. Transmission electron microscopy, SAED diffraction pattern and X-ray photoelectron spectroscopy confirmed the presence of a-GaN QDs with particle size of 7.9, 6.9, 4.4nm under the Ar gas pressures of 50, 100 and 200 Pa, respectively. The room temperature PL and absorbance spectra showed a strong band emission centered at 3.9 eV in a-GaN QDs made under the gas pressures of 100 and 200 Pa, which is nearly 0.5eV blueshifted with respect to the bulk crystal band gap.

• 한국결정성장학회지
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• 제14권1호
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• pp.33-36
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• 2004

고밀도 GaN 타겟의 레이저 어블레이션으로 상온에서 비정질 GaN 박막을 제조하였다. 다양한 Ar 압력 및 레이저 에너지로 증착된 박막의 표면미세구조 및 조성분석 결과, 10Pa의 압력하에 증착된 박막은 smooth한 표면을 갖는 비정질 GaN로 구성되었음을 확인하였으며, 특히 200mJ/pu1se로 증착된 박막은 저 에너지에서 증착된 박막과 비교하여 결정성의 증가 및 화학양론에 가까운 조성을 나타냈다. 상온 photoluminescence spectra로부터 비정질 GaN 박막은 약 2.8eV에서 강한 band gap발광특성이 관측되었으며, 200mJ/pu1se의 10 Pa에서 가장 높은 발광효율을 나타냈다.

• Bulletin of the Korean Chemical Society
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• 제31권6호
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• pp.1638-1642
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• 2010

Mesoporous carbon CMK-3s with different textural properties have been used for the adsorption of phenol to understand the necessary physicochemical properties of carbon for the efficient removal of phenol from contaminated water. The kinetic constants (both pseudo-second order and pseudo-first-order kinetics) increase with increasing pore size of carbons. The maximum adsorption capacities correlate well with micropore volume compared with surface area or total pore volume even though large pore (meso or macropore) may contribute partly to the adsorption. The pore occupancies also explain the importance of micropore for the phenol adsorption. For efficient removal of phenol, carbon adsorbents should have large micropore volume and wide pore size for high uptake and rapid adsorption, respectively.

• Applied Microscopy
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• 제51권
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• pp.1.1-1.2
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• 2021

We demonstrate a fabrication of an atomically controlled single-crystal heart-shaped nanostructure using a convergent electron beam in a scanning transmission electron microscope. The delicately controlled e-beam enable epitaxial crystallization of perovskite oxide LaAlO₃ grown out of the relative conductive interface (i.e. 2 dimensional electron gas) between amorphous LaAlO₃/crystalline SrTiO₃.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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• pp.861-864
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• 2004

본 연구에서는 Ta이 도핑된 $TiO_2$와 $Au/TiO_2$ nanocomposite 박막을 co-sputtering법으로 제작하였다. Ta-doped $TiO_2$ 박막은 금흥석(rutile)에서 아나타제 상으로 변하는 구조를 유도하는 고용체를 형성했다. $Au/TiO_2$ nanocomposite film의 경우에는, 지름이 약 15 nm인 Au particles들이 $TiO_2$ matrix에 균질하게 분포되었다. Ta가 도핑된 $TiO_2$ 전극과 $Au/TiO_2$ 나노 콤포사이트 전극의 anodic photocurrents가 UV뿐만 아니라 가시광선 영역에서도 관찰되었다. Ta이 도핑된 $TiO_2$ 전극과 $Au/TiO_2$ 나노 콤포사이트 사이의 가시광선 영역에서 photoresponse는 계면 상태로 부터의 bandgap의 감소와 전자의 photoexcitation 때문이다.

• 한국결정성장학회지
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• 제13권2호
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• pp.79-82
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• 2003

ArF(193nm) 엑시머 레이저를 이용한 펄스레이저증착법(PLD)에 의해 GaN 소결체를 타겟 재료로 하여 $SiO_2$기판위에 GaN nanoparticles를 합성하였다. PLD 공정 중에는 100Pa, 50Pa, 10Pa및 1 Pa의 Ar gas 압력과 100mJ 및 200mJ의 레이저 에너지를 가하였다. 합성된 GaN nanoparticles는 XRD, SEM, TEM, XPS 및 optical absorption spectra 등에 의해 분석되었다. 합성된 GaN nanoparticles는 대체적으로 20~30nm의 입경을 갖는 균일한 분포를 하고 있었다. 또한, Ar 기체 압력이 낮아짐에 따라 합성된 GaN nanoparticles의 stoichiometry가 향상되고 optical band edge가 blueshift 경향을 나타내었다.

• Bulletin of the Korean Chemical Society
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• 제25권1호
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• pp.63-68
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• 2004

Sugar-based gelator p-dodecanoyl-aminophenyl- ${\beta}$-D-aldopyranosides (1-3) have been shown to self-assemble in the presence of p-aminophenyl aldopyranosides. The hydrogel 1+4 showed the double-helical structure with 3-25 nm outer diameters, which is quite different from that of 1. The gel 2+5 revealed twisted ribbon structure with 30-50 nm in widths and a few micrometers of length whereas the gel 3+4 revealed the single and the bundled fiber structures. The difference in these gel supramolecular structures has successfully been transcribed into silica structures by sol-gel polymerization of tetraethoxysilane (TEOS), resulting in the doublehelical, the twisted-ribbon, the single and the multiple (lotus-shaped) hollow fiber structures. These results indicate that novel silica structures can be created by transcription of various superstructures formed in binary gels through the hydrogen-bonding interaction, and the amino group of the p-aminophenyl aldopyranosides acts as an efficient driving force to create novel silica nanotubes. Furthermore, electron energy-loss spectroscopy (ELLS) provided strong evidence for the inner hollow structure of the double-helical silica nanotube. This is a novel and successful example that a variety of new silica structures can be created using a library of carbohydrate gel fibers as their templates.

• STI Policy Review
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• 제3권2호
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• pp.152-171
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• 2012

In April 2001, many Japanese national institutes were reorganized as Independent Administrative Institutions (IAI) based on the General Act for Independent Administrative Institutions and the act for each institution. Under the Ministry of Education, Culture, Sports, Science and Technology (MEXT), the National Institute for Materials Science (NIMS) was established by the merger of the National Research Institute for Metals (NRIM) and the National Institute for Research in Inorganic Materials (NIRIM). One of the biggest changes was the expansion of autonomous administration. The nanotechnology and material R&D field was prioritized in the 2nd (2001-2005) and the 3rd (2006-2010) Science and Technology Basic Plans; subsequently, NIMS was assigned to take the initiative in nanotechnology as well as materials science. NIMS has proactively expanded research fields through the introduction of researchers from polymers, electronics, and biotechnology as well as member institutes of the World Materials Research Institute Forum (WMRIF). Globalization has been promoted through programs that include the International Center for Young Scientists (ICYS) and the International Center for Materials Nanoarchitectonics (MANA). The 4th Science and Technology Basic Plan (2011-2015) emphasizes outcomes-recovery and rebirth from the disaster, green innovation, and life innovation. The Midterm Plan for NIMS also follows it. R&D collaboration by multi-partners (that include industry, university, and GRI) should be strategically promoted where GRI are especially required to play a hub function for innovative R&D and open innovation. NIMS highlights are Tsukuba Innovation Arena (TIA) and the Nanotechnology Platform Project. On January 20, 2012, a new organization was decided on by the Japanese Government where several IAI from different science and technology areas will be merged to realize more effective R&D as well as administrative cost reductions. NIMS is also supposed to be merged with 4 other R&D IAI under MEXT by the end of 2013.