• Title/Summary/Keyword: Diamond Films

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Effects of Oxygen and Nitrogen Addition on the Optical Properties of Diamond-Like Carbon Films (산소와 질소의 첨가에 따른 DLC막의 광학적 특성의 변화)

  • Hwang, Min-Sun;Lee, Chong-Mu;Moon, Jong
    • Korean Journal of Materials Research
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    • v.7 no.12
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    • pp.1047-1051
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    • 1997
  • CH$_{4}$와 H$_{2}$의 혼합가스에 미량의 질소와 산소를 첨가하여 rf-플라즈마 CVD법으로 DLC막을 합성하였다. 이 때 챔버내 압력은 430mtorr, 기판에 인가된 전력은 80W였으며, H$_{2}$와 CH$_{4}$의 비율은 1:1이었다. 이 시편들에 대해 가시광선 영역과 자외선 영역에서의 투과도를 비교하였으며, 결합구조의 변화를 알아보기 위하여 FTIR 분석을 실시하였다. 질소의 경우 첨가량이 6.3%에서 17.4%으로 증가됨에 따라 전체적인 투과도값이 증가하였으며, FRIR 분석결과 wavenumber 3500 $cm^{-1}$ /의 위치에 N-H stretching band가 나타나고 2300$cm^{-1}$ /에는 nitrile의 피크가 나타났다. 이 피크들의 존재는 질소의 첨가에 의하여 interlink를 감소시킴으로써 막의 잔류응력을 현저히 감소시킬 수 있음을 의미한다. 2% $O_{2}$를 첨가한 경우 막의 투과도는 질소를 첨가한 경우보다 월등히 더 향상되었다. 질소첨가량을 증가시킴에 따라 optical band gap또한 증가되는 경향을 보였으며, 2% $O_{2}$를 첨가하였을 때 막의 optical band gap은 0.5까지 감소하였다.

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Effects of Chemical Vapor Deposition Parameters on The Hardness and the Structural Characteristics of TiN Film (TiN피막의 경도 및 구조적 특성에 미치는 화학증착 조건의 영향)

  • Shin, Jong-Hoon;Lee, Seong-Rae;Baek, Young-Hyun
    • Journal of the Korean institute of surface engineering
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    • v.20 no.3
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    • pp.106-117
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    • 1987
  • The microhardness and the structural characteristics of the chemically vapor deposited TiN film on the 430 stainless steel substrate have been investigated with various deposition parameters such as the deposition time, the total flow rate, the flow rate ratio $(H_2/N_2)$, and the deposition temperature. The most important factor to affect the microhardness of the TiN film in this study was the denseness of the structure in connection with the degree of the lattice strain. The relationship between the lattice parameter changes and the grain size variation under all deposition conditions generally followed the grain boundary relaxation model. The (111) preferred orientation prevailed in the early stage of the deposition conditions, however, the (200) preferred orientation was developed in the later stage. The surface morphology at optimum conditions displayed a dense diamond shaped structure and the microhardness of the films was high (1700-2400Hv) regardless of the type of the substrates used.

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A Study on the Structural Characteristics of Spencer Jacket in Empire Style$(1789{\sim}1820)$ (엠파이어 스타일 시대$(1789{\sim}1820)$ 스펜서 재킷의 구성적 특징에 관한 연구)

  • Choi, Mi-Kyung;Jo, Jin-Sook;Choi, Jin-Hee
    • The Research Journal of the Costume Culture
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    • v.14 no.1
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    • pp.142-152
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    • 2006
  • The purpose of the study was to demonstrate how to recreate Spencer jacket of Empire Style in an attempt to apply this historic style to theatrical costumes and other high fashion items in modern times. The study was carried out through 2 steps. First, Literature, films and other visual information were utilized in order to classify the designs of Spencer jacket. Second, Production of Spencer jacket using patterns shown in literatures and those commercially used and commercial patterns were investigated to find out design characteristics of jackets. Results and discussions are as follows: The results showed that Spencer jacket can be categorized into following three styles: (1) Jackets having front opening without button stands and standing collar, (2) Double breasted opening and notched collar, (3) Single breasted opening and flat collar with waist band. The characteristics of Spencer jacket design were as follows: (1) Short jacket length, (2) Armhole line moved inwards, (3) Long fit shaped puff sleeves, whose puff being distributed more heavily over back of the sleeve, (4) Diamond shaped back bodice, which are consisted with princess lines and shoulder lines moved backwards.

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Effect of Deposition Conditions on the Morphology of MPECVD Diamond Thin Films (MPECVD 다이아몬드 박막의 표면 형상에 미치는 증착조건의 영향)

  • Choe, Ji-Hwan;Lee, Se-Hyeon;Lee, Yu-Gi;Park, Jeong-Il;Lee, Eun-A;Park, Gwang-Ja;Park, Jong-Wan
    • Korean Journal of Materials Research
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    • v.7 no.5
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    • pp.365-373
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    • 1997
  • 다이아몬드 형성에 미치는 MPECVD 증착조건에 관하여 연구하였다. 증착 실험 기판은 Si p-type (100)wafer를 사용하였으며 다이아몬드 박막은 다음과 같은 조건하에서 증착되었다. 메탄 농도:0.75%(3scm)-3%(12scm),산소 농도:0%-0.5%(2scm), 반응 압력:20torr-80torr, 반응 온도:$600^{\circ}C$-90$0^{\circ}C$. 낮은 증착온도($600^{\circ}C$)에서는 (100)의 우선성장면을 보였고 온도가 증가함에 따라 (100)과 (111)이 혼재된 cubo-octahedron이 형성되었고 90$0^{\circ}C$에서는 (111)의 우선성장면을 가징 octahedron이 형성되었다. 산소가 첨가됨에 따라 높은 메탄농도에서도 양질의 다이아몬드가 형성되었다. 낮은 압력하(200torr)에서는 비정질탄소가, 높은 압력하(80torr)에서는 양질의 다이아몬드가 형성되었다.

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Study on Adhesion of DLC Films with Interlayer (중간층을 이용한 DLC 박막의 밀착력에 관한 연구)

  • Kim, Gang-Sam;Cho, Yong-Ki
    • Journal of the Korean institute of surface engineering
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    • v.43 no.3
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    • pp.127-131
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    • 2010
  • Adhesion of DLC film is very significant property that exhibits wear resistance, chemical inertness and high hardness when being deposited to metal substrate. This study was considered that change adhesion of DLC film produced by Plasma Enhanced Chemical Vapor Deposition can be presented through inserting interlayer (Cr, Si-C:H). The thickness of interlayer was result of changing adhesion and residual stress. It was showed that the maximum 12 N of adhesion is on DLC film of Cr interlayer, and that a tendency is to be increased residual stress depend on the thickness. DLC film of Si-C:H interlayer represented 16 N of adhesion at $1{\mu}m$, whereas adhesion is decreased when the thickness is increased. For the interlayer at multi-layer, it was the best that adhesion of Cr/Si-C:H/DLC film was 33 N. Si-C:H interlayer at DLC film controled adhesion of the whole film. It was relaxed the internal stress of DLC film produced by inserting Cr, Si-C:H interlayer.

ESR dosimetry and Dating toward $21^{st}$ Century

  • Ikeya, Motoji
    • Journal of the Korean Magnetic Resonance Society
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    • v.6 no.2
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    • pp.84-88
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    • 2002
  • Dating and dosimetry using electron spin resonance (ESR) in 20th Century developed at both Yamaguchi University and Osaka University have been reviewed with emphasis on new prospects and strategies in 21th century. Natural radiation have been generating radicals that accumulated in archaeological and geological materials. ESR detects these radicals and the ESR signal intensity is proportional to the radiation dose and therefore the age. The assessment of the total dose of natural radiation and the annual dose rate give their ESR ages. The ESR dating of stalactites and stalagmites ant Akiyoshi cave in Yamaguchi prefecture in 1975 was extended to anthropological dating using bones and tooth enamel excavated in Greek Petralona cave. Fossils of shells and corals gave the ages of marine terraces and sea-level changes. Quartz grains gave the ages of geothermal alteration and fault movements. Future ESR dating of ices at outer planets anf their satellite are also investigated as basic studies for ices od $H_2O,\;CO_2,\;SO_2$ as well as terrestrial hydrates in laboratory. Atomic bomb radiation dosimetry at Hiroshima and Nagasaki using ESR lead to the dosimetry of personnel, Chemobyl and JCO criticality accidents. Monitoring of radiation dose with sensitive materials with tissue equivalence are being developed. finally a new scanning ESR imaging apparatus (a near field microwave microscope) developed in our laboratory gave ESR images of Radicals from fossils to Si-CVD and diamond films as summarized in my book in 2002.

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Solid Lubrication Characteristics of DLC Coated Alumina Seals in High Temperature

  • Ok, Chul-Ho
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.06a
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    • pp.356-356
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    • 2007
  • Plasma immersion ion beam deposition (PIIBD) technique is a cost-effective process for the deposition of diamond like carbon thin film, the possible solid lubricant on large surface and a complex shape. We used PIIB process for the preparation of DLC thin film on $Al_2O_3$ with deposition conditions of deposition temperature range $200^{\circ}C$, working gas pressure of 1.310-1Pa. DLC thin films were coated by $C_2H_2$ ion beam deposition on $Al_2O_3$ after the ion bombardment of SiH4 as the bonding layer. Energetic bombardment of $C_2H_2$ ions during the DLC deposition to ceramic materials generated mixed layers at the DLC-Si interface which enhanced the interface to be highly bonded. Wear test showed that the low coefficient of friction of around 0.05 with normal load 2.9N and proved the advantage of the low energy ion bombardment in PIIBD process which improved the tribological properties of DLC thin film coated alumina ceramic. Furthermore, PIIBD was recognized as a useful surface modification technique for the deposition of DLC thin film on the irregular shape components, such as molds, and for the improvement of wear and adhesion problems of the DLC thin film, high temperature solid lubricant.

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Generation of Tilt in the nematic liquid crystal using a-C:H Thin Films Deposited Using PECVD Method (PECVD 장치를 사용하여 증착된 a-C:H 박막을 이용한 네마틱 액정의 틸트 발생)

  • Park, Chang-Joon;Hwang, Jeoung-Yeon;Seo, Dae-Shik;Ahn, Han-Jin;Kim, Kyeong-Chan;Baik, Hong-Koo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.11a
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    • pp.469-472
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    • 2003
  • The nematic liquid crystal (NLC) aligning capabilities using a-C:H thin film deposited at the three kinds of rf bias condition were investigated. A high pretilt angle of about $11^{\circ}$ by the ion beam alignment method was observed on the a-C:H thin film (polymer-like carbon) deposited at 1W rf bias condition, and the low pretilt angle of the NLC was observed on the a-C:H thin film(diamond-like carbon) deposited at rf 30W and 60W bias condition. Consequently, the high NLC pretilt angle and the good aligning capabilities of LC alignment by the IB alignment method on the a-C:H thin film deposited at 1W rf bisa condition can be achieved.

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Second Harmonic Rotational Anisotropy of Polycrystalline Fe Films on Glass Substrates (유리 위에 증착된 다결정 Fe 자성박막의 이차조화파 회전 이방성)

  • Lee, Feel;Jeong, Jae-Woo;Lee, Hun-Sung;Lee, Kyung-Dong;Kim, Ji-Wan;Shin, Sung-Chul
    • Journal of the Korean Magnetics Society
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    • v.19 no.2
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    • pp.47-51
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    • 2009
  • The surface structure of polycrystalline Fe films of various thicknesses on glass substrates have been studied using a Ti: Sapphire laser at 780 nm. We found that the surface structure possesses C$_s$ crystal structure close to $C_{2v}$ through symmetry consideration. We present one-fold intensity profile with one mirror plane in second harmonic (SH) intensity as a proof of $C_s$ symmetry. $C_s$ and $C_{2v}$ surface symmetries usually appear at the (110) surface of a cubic diamond single crystal [1]. Therefore this surface symmetry would be related to bcc (110) growth orientation coinciding with XRD measurement. Further we treated surface normalized SH asymmetry with various thicknesses. The SH asymmetry increases with increasing of film thickness. From these results, it is observed that the surface structure of thin polycrystalline Fe film below 5 nm is almost isotropic, while in the case of the thicker Fe films, surface structure have $C_s$ symmetry structure close to $C_{2v}$.

The effects of solenoid magnet on plasma extraction in Filtered Vacuum Arc Source (FVAS) (자장여과 아크 소스에서 각 전자석이 플라즈마 인출에 미치는 영향)

  • 김종국;변응선;이구현;조영상
    • Journal of the Korean Vacuum Society
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    • v.10 no.4
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    • pp.431-439
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    • 2001
  • In this paper, the a-Diamond films were synthesized using filtered vacuum arc source (FVAS), FVAS was composed of a torus structure with bending angle of 60 degree. The radius of torus was 266 mm, the radius of plasma duct was 80 mm and the total length was 600 mm. The magnet parts were composed of one permanent magnet and five solenoid magnets. The plasma duct was electrically isolated from the ground so that a bias voltage could be applied. The baffles inside plasma duct were installed in order to prevent the recoil effect of macro-particles. Cathode was made of graphite with 80 mm in diameter. The effects of solenoid magnet on plasma extraction were investigated by computer simulation and experiment using Taguchi's methode. The source and extraction magnet affected the arc stabilization. The extraction beam current was maximized with low value of the source magnet current and high value of the filtering magnet current. The beam current density was 3.2 mA/$\textrm{cm}^2$ and average deposition rate was 5 $\AA$/sec when the currents of arc discharge, source, extraction, bending, deflection and outlet magnet were 30 A, 1 A, 3 A, 5 A, 5 A, and 5 A, respectively. The beam current density and the efficiency of beam transportation were increased with the positive bias voltage of the plasma duct.

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