• 한국전기전자재료학회논문지
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• 제27권1호
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• pp.18-21
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• 2014

Because the Pb-based piezoelectric materials showed problems such as an environmental pollution. lead-free $O_3$ materials were studied in the present study. The $O_3$ thin films were deposited at $640^{\circ}C$ on $Pt/Ti/SiO_2$ substrate by pulsed laser deposition (PLD) and were annealed for 5 min at $750^{\circ}C$ using rapid thermal annealing (RTA) in nitrogen atmosphere. Samples annealed at $750^{\circ}C$ showed a smooth morphology and an improvement of the dielectric and leakage properties, as compared with as-grown samples. However, electrical properties of the $O_3$ thin films obtained in the present study should be improved for piezoelectric applications.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 추계학술대회 논문집
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• pp.598-601
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• 2000

We investigated the fabrication of Si nanoparticle and $C_{60}$ thin films by pulsed laser ablation. As a result, we observed visible green photoluminescence spectra in the Si/C$_{60}$ multilayer films after laser annealing. It is considered that this green photoluminescence is occurred from SiC particles, which is produced reaction of Si nanoparticles with $C_{60}$ via laser annealing.ing.

• 한국기계가공학회지
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• 제14권6호
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• pp.136-141
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• 2015

Laser surface polishing is a polishing method for improving surface roughness using an integrated laser beam. Using a laser for surface polishing can improve the surface condition without physical contact or chemical action. Laser polishing has mainly been used to polish the surface of diamond or optical articles, such as lenses and glasses. Recently, diverse studies on laser polishing for metals have been conducted. The analytic study of laser surface polishing has been conducted with experimental trials for comparison, so that the proper conditions for laser polishing can be recommended. In this study, laser surface polishing was simulated in order to predict the heat-affected zone on the die steel depending on the power of the pulsed laser. The simulated results were verified by comparing them to those of the experimental trials. Through this study, therefore, the application of FEM to the selection of appropriate laser conditions could be possible.

• 한국레이저가공학회지
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• 제8권1호
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• pp.27-37
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• 2005

During laser spot welding of the braun tube electron gun, phenomena such as serious spattering and oxidative reaction, etc. were occurred. The spatter occurred from weld pool affects the braun tube, namely it blocks up a very small hole on the shadow mask and causes short circuit between two poles of the electron gun. We guessed that high power density and oxidative reaction are main sources of these problems. So, we studied to prevent and to reduce spatter occurring in spot welding of the braun tube electron gun using pulsed Nd:YAG laser. The characteristics of laser output power was estimated, and the loss of laser energy by optical parameter and spatter was measured by powermeter. The effects of welding parameters, laser defocused distance and incident angle, were investigated on the shape and penetration depth of the laser welded bead in flare and flange joints. From these results, the laser peak power was a major factor to control penetration depth and to occur spatter. It was found that the losses of laser energy by optic parameter and sticked spatter affect seriously laser weldability of thin sheets.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 춘계학술대회 논문집
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• pp.231-232
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• 2010

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 1998년도 특별강연 및 추계학술발표 개요집
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• pp.183-184
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• 1998

• Bulletin of the Korean Chemical Society
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• 제33권1호
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• pp.29-30
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• 2012

• Bulletin of the Korean Chemical Society
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• 제22권8호
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• pp.921-924
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• 2001

• 한국자기학회:학술대회 개요집
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• 한국자기학회 1999년도 추계연구발표회 논문개요집
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• pp.68-69
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• 1999

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제52권6호
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• pp.231-234
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• 2003

ZnO thin films on (100) p-type silicon substrates have been deposited by pulsed laser deposition(PLD) technique using an Nd:YAG laser with a wavelength of 266nm. The influence of the deposition parameters, such as oxygen pressure, substrate temperature and laser energy density variation on the properties of the grown film, was studied. The experiments were performed for oxygen gas flow rate of 100~700 sccm and substrate temperatures in the range of 200~$500^{\circ}C$. We investigated the structural and morphological properties of ZnO thin films using X-ray diffraction(XRD), scanning electron microscopy(SEM) and atomic force microscopy(AFM).