• 소성∙가공
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• 제29권3호
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• pp.127-134
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• 2020

It is known that the difference of texture of the polycrystalline Al sheet is not a critical parameter for the formation of aligned nanopore arrays in anodic aluminum oxide (AAO). This will be related to the polycrystalline grain in the Al sheet. The texture of each grain in the polycrystalline Al sheet is different. The mixed textures of grains have the mixing effects on the nanopore structure of the AAO. Thus, the effect of Al texture on the nanopore structure of the AAO was investigated using three types of Al single crystals with (111), (200) and (220) textures in this paper. These three types of AAO layers were fabricated by the two-step anodizing method at 40 V and temperature of 0-5℃ in oxalic acid solution. In the nanopores formed on the AAO, the average area of one nanopore and the average roundness of one nanopore were measured were measured based on the SEM images. In the hexagon obtained by connecting nanopores on the AAO, the average standard deviation of one angle deviated from 120° was measured. In the AAO nanopores with texture of (111), (200) and (220) single crystal samples, the average area of one nanopore of (200) single crystal sample was the widest, followed by (111), (220) single crystals. The average circularity of one nanopore of (200) single crystal sample was the best, followed by (111), (220) single crystals. The average standard deviation of an angle from 120° of (220) single crystal sample was the largest, followed by (111) and (200) single crystals.

• 반도체디스플레이기술학회지
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• 제20권1호
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• pp.37-41
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• 2021

We report on the formation of anodic aluminum oxide (AAO) film using sulfuric acid containing cerium salt. When the temperature of the sulfuric acid containing cerium salt changes from 5 ℃ to 20 ℃, the current density and the thickness growth rate increase. The surface morphology of the AAO film change according to the temperature of the electrolytes. And that affected the breakdown voltage and the plasma etch rate. The breakdown voltage per unit thickness was the highest at 15 ℃, and the plasma etch rate was the lowest at 10 ℃ at 2.80 ㎛/h.

• 공업화학
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• 제16권4호
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• pp.461-473
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• 2005

나노 기술은 현대 과학에 있어서 가장 주목 받고 있는 분야이며, 특히 나노미터 크기의 디멘션(dimension)을 가지는 나노 구조물의 제작은 나노 기술 연구의 출발점이며, 핵심 요소이다. 양극산화 알루미나 나노 템플레이트(anodicaluminum oxide or AAO nanotemplate) 기술은 상대적으로 공정이 쉽고 경제적이며, 대면적으로 나노 템플레이트의 제작이 가능하다는 장점을 가지고 있다. 또한 현재의 리소그래피 기술로는 달성하기 어려운 수준의 매우 큰 종횡비(aspect ratio)를 가능하게 하고, 조건을 변화시킴에 따라서 나노 템플레이트 기공의 직경 및 길이, 기공 밀도의 조절이 용이하다는 장점을 가지고 있어서 최근 10여 년간 매우 활발하게 이와 관련된 연구가 진행되어 왔으며, 다양한 나노 기술 분야로의 응용이 기대된다. 본 총설에서는 양극산화 알루미나 나노 템플레이트의 제조 및 응용에 대해 기술하였다.

• Journal of Electrical Engineering and Technology
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• 제10권6호
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• pp.2364-2367
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• 2015

In this study, we fabricated an electrolyte-insulator-metal (EIM) device incorporating a high-k Al₂O₃ sensing membrane using a porous anodic aluminum oxide (AAO) through a two-step anodizing process for pH detection. The structural properties were observed by field-emission scanning electron microscopy (FE-SEM) and X-ray diffraction patterns (XRD). Electrochemical measurements taken consisted of capacitance-voltage (C-V), hysteresis voltage and drift rates. The average pore diameter and depth of the AAO membrane with a pore-widening time of 20 min were 123nm and 273.5nm, respectively. At a pore-widening time of 20 min, the EIM device using anodic aluminum oxide exhibited a high sensitivity (56mV/pH), hysteresis voltage (6.2mV) and drift rate (0.25mV/pH).

• Journal of Information Display
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• 제2권3호
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• pp.78-85
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• 2001

The growth of carbon nanotubes(CNTs) in anodic aluminum oxide(AAO) template and their application to a field emitter are described. AAO templates were fabricated by anodizing bulk aluminum and sputtered thin Al film on Nb-coated Si wafers. After Co catalyst had been electrochemically deposited into the bottom of the pores in AAO template, CNTs were grown by pyrolyzing $C_2H_2$. Depending on the reaction conditions, CNTs grew up to or over the top of the pores in AAO template with different structures. The morphology and structure of CNTs were observed with a scanning electron microscope and a transmission electron microscope. The diameter of CNTs strongly depended on the size of the pores in AAO template and the growing conditions. The electron field emission measurement of the samples resulted in the turn-on field of 1.9-2.2 $V/{\mu}m$ and the field enhancement factor of 2450-5200. The observation of high field enhancement factors is explained in terms of low field screening effect.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2010년도 춘계학술대회
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• pp.814-817
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• 2010

다공성 알루미나 나노틀은 2단계의 양극산화 과정에 의해 세공의 직경이 균일하며, 배열이 규칙적이며 나노틀에 완벽하게 수직으로 배향되어 있다. 게다가 세공의 직경과 세공간의 간격은 양극산화시 전압과 전해질등을 바꾸어 주면 쉽게 조절할 수 있다. 금속을 세공내에 전기 화학적으로 탐지하면 각 세공 내에 규칙적인 직경의 금속 나노선이 생성된다.

• 전기화학회지
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• 제12권1호
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• pp.47-53
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• 2009

본 연구에서는 불순물이 포함된 Al 기판으로부터 두 단계의 양극산화 (anodization) 법에 의해 균일한 나노기공을 갖는 AAO(Anodic Aluminum Oxide)을 제조하였다. 생성된 AAO템플릿 위에 Deposition-Precipitation(DP)방법을 사용하여 수직으로 형성된 $TiO_2$ 나노섬유에 Au를 첨가시켜 2 wt.% $Au/TiO_2$ 나노섬유룰 제조하였다. 두 단계의 양극산화를 통해 규칙적으로 배열된 AAO 기공 형상과 기판 위에 수직으로 배향된 $TiO_2$ 나노섬유의 형상을 SEM을 통해 확인하였다. 또한 $Au/TiO_2$ 나노섬유의 특성은 XRD와 Raman 분석을 통하여 $TiO_2$의 아나타제(anatase)와 루타일(rutile) 결정구조와 $TiO_2$ 나노섬유에 담지된 Au의 존재를 확인하였다. 또한 일산화탄소(CO) 산화반응을 통해 AAO(Anodic Aluminum Oxide)기판 위에 형성된 $TiO_2$와 2 wt% $Au/TiO_2$ 나노섬유의 광촉매적 활성을 비교하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.268-268
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• 2010

AC anodizing on aluminum foil was investigated by the variation of AC voltage and frequency. The voltage and frequency were applied in the range of approximately 40~200V, 0~400Hz. The porous alumina film was formed and the growth rate of oxide film is increased with frequency. The structural property was analyzed by SEM and XRD. SEM results show the approximate relation between frequency, voltage and growth rate. The AC voltage effect on the structural modulation of porous alumina indicates that AC anodizing is useful for the application to nanocapacitor material.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2016년도 추계학술대회 논문집
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• pp.152-152
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• 2016

Anodizing is a technology to generate thicker and high-quality films than natural oxide films by treating metals via electrochemical methods. It is a technique to develop metals for various uses, and extensive research on the commercial use has been performed for a long time. Aluminum anodic oxide (AAO) is generate oxide films, whose sizes and characteristics depending on the types of electrolytes, voltages, temperatures and time. Electrochemical manufacturing method of nano structure is an efficient technology in terms of cost reduction, high productivity and complicated shapes, which receives the spotlight in diverse areas. The sulfuric acid was used as an anodizing electrolyte, controlling its temperature to $10^{\circ}C$. The anode was 5083 Al alloy with dimension of $5(t){\times}20{\times}20mm$ while the cathode was the platinum. The distance between the anode and the cathode was maintained at 3 cm. Agitation was introduced by magnetic stirrer at 300 rpm to prevent localized temperature rise that hinders stable growth of oxide layer. In order to observe surface characteristics with applied current density, the electrolyte temperature, concentration was maintained at constant condition for $10^{\circ}C$, 10 vol.%, respectively. To prevent hindrance of stable growth of oxide layer due to local temperature increase during the experiment, stirring was maintained at constant rate. In addition, using galvanostatic method, it was maintained at current density of $10{\sim}30mA/cm^2$ for 40 minutes. The cavitation experiment was carried out with an ultrasonic vibratory apparatus using piezo-electric effect with modified ASTM-G32. The peak-to-peak amplitude was $30{\mu}m$ and the distance between the horn tip and specimen was 1 mm. The specimen after the experiment was cleaned in an ultrasonic, dried in a vacuum oven for more than 24 hours, and weighed with an electric balance. The surface damage morphology was observed with 3D analysis microscope. As a result of the investigation, differences were observed surface hardness and anti-cavitation characteristics depending on the development of oxide film with applied current density.

• 전기화학회지
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• 제8권3호
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• pp.125-129
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• 2005

본 연구에서는 고순도 알루미늄 호일$(t=300{\mu}m)$양극산화 공정을 통해 AAO 나노템플레이트를 자체 제조하였고, 이렇게 제조된 형틀을 가지고 교류 나노전주법에 의해 경자성 합금인 CoP와 연자성 합금인 CoFe를 나노와이어로 제조하였다. 대표적인 Co계 자성합금인 CoP와 CoFe나노와이어는 각기 독특한 자기적 성질을 나타내었다. 경자성 CoP 합금 나노와이어의 경우 교류 인가전압에 따라 hcp와 fcc가 혼재된 구조가 형성되어 자기적 특성에 영향을 미쳤다. 또한 높은 포화자화 값을 갖는 CoFe연자성 합금 나노와이어는 박막 도금 시와는 달리 이상합금도금현상이 거의 나타나지 않았으며 $Co_{30}Fe_{70}$에서 가장 좋은 238emu/g의 포화자화 값을 나타내었다.