• 제목/요약/키워드: Nanoscale Structure

검색결과 158건 처리시간 0.029초

유기 자기조립 단분자막의 레이저 포토 패터닝을 이용한 박막 미세 형상 가공 기술 (Micromachining Thin Film Using Femtosecond Laser Photo Patterning Of Organic Self-Assembled Monolayers.)

  • 최무진;장원석;김재구;조성학;황경현
    • 한국정밀공학회지
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    • 제21권12호
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    • pp.160-166
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    • 2004
  • Self-Assembled Monolayers(SAMs) by alkanethiol adsorption to thin metal film are widely being investigated fer applications as coating layer for anti-stiction or friction reduction and in fabrication of micro structure of molecule and bio molecule. Recently, there have been many researches on micro patterning using the advantages of very thin thickness and etching resistance of Self-Assembled Monolayers in selective etching of thin metal film. In this report, we present the several machining method to form the nanoscale structure by Mask-Less laser patterning using alknanethiolate Self-Assembled Monolayers such as thin metal film etching and heterogeneous SAMs structure formation.

Ultrahuge Light Intensity in the Gap Region of a Bowtie Nanoantenna Coupled to a Low-mode-volume Photonic-crystal Nanocavity

  • Ebadi, Nassibeh;Yadipour, Reza;Baghban, Hamed
    • Current Optics and Photonics
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    • 제2권1호
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    • pp.85-89
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    • 2018
  • This paper presents a new, efficient hybrid photonic-plasmonic structure. The proposed structure efficiently and with very high accuracy combines the resonant mode of a low-mode-volume photonic-crystal nanocavity with a bowtie nanoantenna's plasmonic resonance. The resulting enormous enhancement of light intensity of about $1.1{\times}10^7$ in the gap region of the bowtie nanoantenna, due to the effective optical-resonance combination, is realized by subtle optimization of the nanocavity's optical characteristics. This coupled structure holds great promise for many applications relying on strong confinement and enhancement of optical field in nanoscale volumes, including antennas (communication and information), optical trapping and manipulation, sensors, data storage, nonlinear optics, and lasers.

저결함 그래핀 양자점 구조를 갖는 RGO 나노 복합체 기반의 저항성 메모리 특성 (Memristive Devices Based on RGO Nano-sheet Nanocomposites with an Embedded GQD Layer)

  • 김용우;황성원
    • 반도체디스플레이기술학회지
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    • 제20권1호
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    • pp.54-58
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    • 2021
  • The RGO with controllable oxygen functional groups is a novel material as the active layer of resistive switching memory through a reduction process. We designed a nanoscale conductive channel induced by local oxygen ion diffusion in an Au / RGO+GQD / Al resistive switching memory structure. A strong electric field was locally generated around the Al metal channel generated in BIL, and the local formation of a direct conductive low-dimensional channel in the complex RGO graphene quantum dot region was confirmed. The resistive memory design of the complex RGO graphene quantum dot structure can be applied as an effective structure for charge transport, and it has been shown that the resistive switching mechanism based on the movement of oxygen and metal ions is a fundamental alternative to understanding and application of next-generation intelligent semiconductor systems.

단결정 구리 나노와이어의 굽힘 특성 (Bending Characteristics of Single Crystalline Copper Nanowires)

  • 정광섭;조맹효
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회A
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    • pp.1896-1901
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    • 2008
  • Single crystalline copper nanowires are subjected to bending tests using molecular dynamics simulations and the embedded atom method. To observe behaviors of nanowire, bending tests are performed for various rates of deflection and different boundary conditions: fixed-free and fixed-fixed. When the deflection of nanowire becomes large, twinnings and dislocations appear, and <100> crystal structure transforms to <110>. At high rates, phase transformation occurs in whole nanowire. But, at low rates, atomic structure changes to <110> phase partially. The final deformed structures are affected by the rate of deflection and boundary conditions. These effects can be important design parameters at nanoscale.

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Carbon Nanotubes and Nanofibre: An Overview

  • Chatterjee, A.;Deopura, B.L.
    • Fibers and Polymers
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    • 제3권4호
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    • pp.134-139
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    • 2002
  • Carbon nanotubes are graphene sheets rolled up in cylinders with diameter as small as 1nm. Extensive work carried out in recent years has revealed the intriguing properties of this novel material. Exceptional property combined with low density of nanotubes makes them suitable for use as reinforcements in composites. Low volume of production and high cost is the main limitations towards their growth and application. Nanofibres bridge the gap between the conventional carbon fibre and the carbon nanotubes. With their low cost & comparatively higher volume of production along with their exceptional properties, the nanofibres are considered attractive material as nanoscale reinforcement. In this article a concise review of structure, property. production and application of carbon nanotubes and nanofibres have been discussed.

The Effect of Cr Dosage on FePt Nanoparticle Formation

  • Won, C.;Keavney, D.J.;Divan, R.;Bader, S.D.
    • Journal of Magnetics
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    • 제11권4호
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    • pp.182-188
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    • 2006
  • The search for high-density recording materials has been one of most active and vigorous field in the field of magnetism. $FePt-L1_{0}$ nanoparticle has emerged as a potential candidate because of its high anisotropy. In this paper, we provide an overview of recent work at Argonne National Laboratory that contributes to the ongoing dialogue concerning the relation between structure and properties of the FePt nanoparticle system. In particular we discuss the ability to control structure and properties via dosing with Cr. Cr-dosed FePt films were grown via molecular beam epitaxy and annealed at $550^{\circ}C$ in an ultrahigh vacuum chamber, and were studied with the surface magneto-optic Kerr effect (SMOKE), scanning electron microscopy (SEM) and x-ray magnetic circular dichroism (XMCD). We found that small dosage of Cr helps to generate $L1_{0}$ phase FePt magnetic nanoparticles with small size, defined shape and regular spatial distribution on MgO (001) substrate. The nanostructures are ferromagnetic with high magnetic coercivity (${\sim}0.9T$) and magnetic easy axis in the desired out-of-plane orientation. We also show that controlling the lateral region where nanostructures exist is possible via artificial patterning with Cr.

유전체 판과 금속 나노선 사이에 구속된 표면 플라즈몬 모드 (Surface Plasmon Modes Confined in the Gap Between Metal Nanowire and Dielectric Slab)

  • 한철웅;오차환;송석호
    • 한국광학회지
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    • 제22권6호
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    • pp.269-275
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    • 2011
  • 회절한계 이하의 모드 크기를 가지는 금속-유전체 혼합 광도파로 구조를 제안하고자 한다. 제안된 혼합 광도파로는 금속 나노선이 유전체 평면 위에 놓인 구조로서, 금속선과 유전체 사이에 구속된 파장보다 작은 크기의 표면-플라즈몬 모드의 특성을 기존의 유전체 나노선을 이용하는 구조와 비교 분석하였다. 두 도파로의 모드 크기와 전파 거리는 나노선의 직경이 큰 경우에는 비슷한 경향을 보이나, 직경이 작아짐에 따라 서로 상이한 값을 가진다. 회절 한계보다 100배 이상 작은 모드를 갖는 파장길이의 나노 공진기 구현을 위해서는 제안된 금속 나노선-유전체 광 도파로 구조가 적합함을 보였다.

Nanowire Reconfigurable Crossbar 구조를 위한 결함 회피형 로직 재할당 방식의 분석과 총 비용에 따른 최적화 방안 (Cost-Driven Optimization of Defect-Avoidant Logic Mapping Strategies for Nanowire Reconfigurable Crossbar Architecture)

  • 이종석;최민수
    • 한국정보과학회논문지:시스템및이론
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    • 제37권5호
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    • pp.257-271
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    • 2010
  • Photolithography 통합 시대의 끝이 빠르게 다가옴에 따라, 최근에는 새로운 나노 스케일의 소재와 집적 방식에 기반을 둔 수많은 나노 스케일 장치와 시스템이 나타나고 있다. 특히 nanowire crossbar 구조를 이용한 다양한 reconfigurable architecture 들이 보고되고 있다. 하지만 아쉽게도 나노 스케일의 구성 요소를 이용한 이러한 고집적 시스템은 생산 단계에서 발생하는 각종 물리적 결함과 오차에 취약하며 따라서 결함에 대한 관용성 즉 defecttolerance는 nanowire reconfigurable crossbar 시스템에 있어 해결해야 할 가장 중대한 문제 중 하나라 할 수 있다. 이에 본 논문에서는 nanowire reconfigurable crossbar 시스템 상에서 사용되어질 수 있는 세 가지의 결함 회피형(defectavoidant) 로직 재할당 알고리듬을 설명하고 다양한 방식으로 평가하였다. 이에 더불어 로직 재할당시에 발생하는 비용과 이로 인해 얻어지는 repair performance를 계량적으로 상호 분석하여 최적화된 repair 방식을 찾아내는 새로운 방안을 소개하였다. 이어 다양한 파라메터들을 이용한 시뮬레이션 결과를 제시함으로써 새로 소개된 cost-driven repair 최적화 방식을 검증하였다.

유한요소법을 이용한 실리콘 기판에서의 공핍 영역 해석 (Depletion region analysis of silicon substrate using finite element methods)

  • 변기량;황호정
    • 대한전자공학회논문지SD
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    • 제39권1호
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    • pp.1-11
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    • 2002
  • 본 논문에서는 나노영역의 고해상도 도핑 농도 측정 장비 개발을 위해 공핍 근사 조건하 복잡한 계산 영역에서 공핍 영역을 간단히 계산할 수 있는 방법을 개발하였다. 개발된 공핍영역 계산 방법은 유한요소법을 이용한 적응분할 포아송 방정식 해석기를 사용하여 대전된 영역의 경계에서 전위가 0인 등고선과 일치하도록 하여 계산하는 방법이다. 이 방법의 타당성을 검증하기 위해 계산된 대전영역 및 전위분포가 공핍영역의 정의에 맞는지 확인하였으며, pn 접합에서의 공핍영역 깊이 및 MOS 구조에서 정전용량을 계산하여 비교해 본 결과 이론치와 정확히 일치함을 알 수 있었다. 이러한 Pn 접합 및 MOS 에서 공핍영역 계산 검증을 바탕으로 나노영역의 탐침을 장착한 SCM에서 전압에 따른 실리콘 내의 공핍영역 모양과 전위를 분석하여, 정전용랑 모델링을 하였으며, 이로부터 CV 곡선과 SCM의 출력인 dC/dV곡선을 계산하였다.

Addition effects of nanoscale NiO on microstructure and superconducting properties of MgB2

  • Ranot, Mahipal;Jang, S.H.;Oh, Y.S.;Shinde, K.P.;Kang, S.H.;Chung, K.C.
    • 한국초전도ㆍ저온공학회논문지
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    • 제18권1호
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    • pp.37-40
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    • 2016
  • We have investigated the addition effect of NiO magnetic nanoparticles on crystal structure, microstructure as well as superconducting properties of $MgB_2$. NiO-added $MgB_2$ samples were prepared by the solid-state reaction method. The superconducting transition temperature ($T_c$) of 37.91 K was obtained for pure $MgB_2$, and $T_c$ was found to decrease systematically on increasing the addition level of NiO. X-ray diffraction (XRD) analysis revealed that no substitution of Ni for Mg in the lattice of $MgB_2$ was occurred. The microstructural analysis shows that the pure $MgB_2$ sample consists of plate shape $MgB_2$ grains, and the grains get refined to smaller size with the addition of NiO nanoparticles. At 5 K, high values of critical current density ($J_c$) were obtained for small amount NiO-added $MgB_2$ samples as compared to pure sample. The enhancement in $J_c$ could be attributed to the refinement of $MgB_2$ grains which leads to high density of grain boundaries in NiO-added $MgB_2$ samples.