• Journal of the Korean institute of surface engineering
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• v.31 no.5
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• pp.251-260
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• 1998

Stainless Steel is being used widely for various purposes due to its good corrosion resistance. There have been many researches to produce colored stainless steel by several methods such as anodizing and ion-plating. In this experiment, we $Ti_XN$(C,O) on the films SUS304, aluminium, and glass substrates with DC magentron sputterinng system made by Leybold Hereus, and strdied the structur, corrsion and pit characture of the TiXN observed by TeM image was black and whink and white columnar hed a very fine(200$\AA$) dense sturcture,and the diffraction resistance at the $3{\times}10_6A/\textrm{cm}^2$ and $10_{10}\times{cm}^2$current density were obtained in the under-stoichiometry $Ti_xN$ compound of Ar/$N_2$(Ar:$N_2$=100:6, titanium-rich compound) and the over-stoichiometry compound of Ar/$N_2$((Ar:$N_2$=60:15) respectively. When the thiness was over 1.64$\mu\textrm{m}$, good pit resistance could be obtained and its improvement was especially affected by perfect surfaceface. Typical TiN anodic polarzation curves of very unstable corrosion were observed by $Ti_xN$ film on the glass and perfect film of 3.28$\mu\textrm{m}$ thickness.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.1
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• pp.58-66
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• 2002

Acousto-optical wavelength tunable optical filters in LiNbO$_3$ have been demonstrated using taperd directional weighted coupling acoustic waveguides and Ti double diffusion technique. Conversion efficiency in excess of 61%, 86% and sidelobe intensity of -14.29㏈, -14.99㏈ were measured at a wavelength of 1551.1nm RF frequency of 173.58MHz and RF power of 35㎽ for both TE and TM input polarizations, respectivelv. A spectral width of ~l.8nm and linear tuning late of 8.6nm/MHz were demonstrated. A 2.82$mutextrm{s}$ switching time has been measured. With two channels with 2.5nmseparation, channel cross-talk was lower than -l4㏈ for single wavelength filtering due to sidelobe.

• Korean Journal of Optics and Photonics
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• v.11 no.3
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• pp.193-197
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• 2000

A polarized mode convertible, wavelength tunable optical filters with acoustic barriers and acousto-optic effect have been produced in LiNb03 substrate utilizing the Ti double diffusion technique. Polarization conversion in excess of 81 % and a spectral width of -200 kHz (-1.83 nm) were achieved at a wavelength of 1551.6 nm and RF frequencies of 173.07 kHz and 173.05 kHz for both transverse electric (TE) and transverse magnetic (lM) input polarizations, respectively. The electrical driving power was 10.97 mW and reduced to about 10% of one for an optical filter without an acoustic barrier. A linear tuning rate of 8.2 nmlMHz and sidelobe intensity of -4 dB was demonstrated. rated.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.7
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• pp.557-564
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• 1998

A low loss x-cut $LiNbO_3$optical waveguide was fabricated by Yi in-diffusion, and the properties of guided-mode and the total insertion loss of the pigtailed waveguide with polarization maintaining fiber(PMF) were measured at optical wavelength 1550nm. for forming the waveguides, the parameters of diffusion, Ti thickness, waveguide line-width, length, diffusion temperature, time and atmosphere were set $1400{\AA}$, $8{\mu}m$, 3.3cm, $1050^{\circ}C$, 8 hours and wet bubbled oxygen, respectively. And then after the polishing and piatailing, it showed that the total insertion loss was -4.1dB for TM mode, -5.5dB for TE mode, and mode size, that is, the horizontal/ vertical size were $13.8{\mu}m/18{\mu}m$ for TM mode, $9.6{\mu}m/6.5{\mu}m$ for TE mode.

• The Bulletin of The Korean Astronomical Society
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• v.45 no.1
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• pp.52.2-52.2
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• 2020

At quasi-perpendicular shocks in the high-�� (��=Pgas/Pmag~100) intracluster medium (ICM), various microinstabilities occur by the temperature anisotropies and/or drift motions of plasma. In the downstream, the Alfvén ion cyclotron instability (AIC) due to the ion temperature anisotropy (Ti⊥>Ti║) is triggered by shock-reflected ions, the whistler instability (WI) is driven by the electron temperature anisotropy (Te⊥>Te║) as a consequence of the shock compression of magnetic fields, and the mirror instability is generated due to the ion and/or electron temperature anisotropy. At the shock foot, the modified two stream instability (MTSI) is possibly excited by the cross-field drift between ions and electrons. In the upstream, electron firehose instability (EFI) is driven by the electron temperature anisotropy or the relative drift between incoming and reflected electrons. These microinstabilities play important roles in the particle acceleration in ICM shocks, so understanding of the microinstabilities and the resultant plasma waves is essential. In this study, based on a linear stability analysis, the basic properties of the microinstabilities in ICM shocks and the ion/electron scale fluctuations are described. We then discuss the implication of our work on the electron pre-acceleration in ICM shocks.

• Korean Chemical Engineering Research
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• v.47 no.6
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• pp.715-719
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• 2009

The phase change electrode board for the bio-information detection through electrical property response of phase change material was developed in this study. We manufactured the electrode board using Aluminum first that is widely used in conventional semiconductor device process. Without further treatment, these aluminum electrodes tend to contain voids in PETEOS(plasma enhanced tetraethyoxysilane) material that are easily detected by cross-sectional SEM(Scanning Electron Microscope). The voids can be easily attacked and transformed into holes in between PETEOS and electrodes after etch back and washing process. In order to resolve this issue of Al electrode board, we developed a electrode board manufacturing method using low resistivity TiN, which has advantages in terms of the step-coverage of phase change($Ge_2Sb_2Te_5$, GST) thin film as well as thermodynamic stability, without etch back and washing process. This TiN material serves as the top and bottom electrode in PRAM(Phase-change Random Access Memory). The good connection between the TiN electrode and GST thin film was confirmed by observing the cross-section of TiN electrode board using SEM. The resistances of amorphous and crystalline GST thin film on TiN electrodes were also measured, and 1000 times difference between the amorphous and crystalline resistance of GST thin film was obtained, which is well enough for the signal detection.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.2
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• pp.146-153
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• 1998

The optical near-field patterns, propagation loss and mode sizes of x-cut $Ti:LiNbO_3$ optical waveguide which was fabricated by Ti-diffusion varying with Ti strip thickness in wet oxygen atmosphere were discussed at optical wavelength 1550nm. As Ti thickness increased from $760{\AA}$, the insertion loss of waveguide was decreased. But at Ti thickness $1500{\AA}$, mode sizes are widely broadened. The Ti thickness of below $1100{\AA}$ and above $1500{\AA}$ showed negative effects to propagation loss and fiber coupling. The best Ti thickness for fabricating low propagation loss and good fiber coupling was inferred to be between $1100{\AA}-1500{\AA}$ in our conditions. And for Ti thickness $1150{\AA}$, its propagation loss, horizontal/vertical mode sizes were showed 1.61 dB/cm, $11.9/8.9{\mu}m$ for TM, 0.22 dB/cm, $12.0/9.1{\mu}m$ for TE respectively.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.20 no.1
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• pp.30-34
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• 2010

$CoSb_3$-based skutterudite compounds are promising candidates as thermoelectric (TE) materials used in intermediate temperature region. In this study, sintering of $CoSb_3$ powder and joining of $CoSb_3$ to copper-molybdenum electrode have been simultaneously performed by spark plasma sintering technique. The Ti foil was used for preventing the diffusion of copper into $CoSb_3$ and the Cu : Mo = 3 : 7 Vol. ratio composition was selected by the consideration of thermal expansion coefficients. The insertion of Ti interlayer between Cu-Mo and $CoSb_3$ was effective to join $CoSb_3$ to Cu-Mo by forming an intermediate layer of $TiSb_2$ at the Ti-$CoSb_3$ boundary. However, the formation of TiSb and TiCoSb intermediate layers deteriorated the joining properties by the generation of cracks in the interface of intermediate layer/$CoSb_3$ and intermediate/intermediate layers.

• Bulletin of the Korean Chemical Society
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• v.28 no.6
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• pp.953-958
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• 2007

Anchoring quantum dots (QDs) onto thermodynamically stable, large band gap oxide semiconductors is a very important strategy to enhance their quantum yields for solar energy conversion in both visible and near-IR regions. We describe a general procedure for anchoring a few chalcogenide QDs onto the titanium oxide layer. To anchor the colloidal QDs onto a mesoporous TiO2 layer, linker molecules containing both carboxylate and thiol functional groups were initially attached to TiO2 layers and subsequently used to capture dispersed QDs with the thiol group. Employing the procedure, we exploited cadmium selenide (CdSe) and cadmium telluride (CdTe) quantum dots (QDs) as inorganic sensitizers for a large band gap TiO2 layer of dye-sensitized solar cells (DSSCs). Their attachment was confirmed by naked eyes, absorption spectra, and photovoltaic effects. A few QD-TiO2 systems thus obtained have been characterized for photoelectrochemical solar energy conversion.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.39 no.1
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• pp.22-30
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• 2002

The nucleation of copper(Cu) with (hfac)iu(VTMS) oganometallic precursor is investigated for Si, $Sio_2$, TiN, $W_2N$ substrates. As the deposition temperature is increased, the dominant growth mechanism is observed to change from the nucleation of Cu particles to the clustering of Cu nuclei around $180^{\ciec}C$, independent of the employed substrates. It is also observed that the cleaning of substrate surfaces with the diluted HF solution improves the selectivity of Cu nucleation between TiN and $Sio_2$ substrates. Dimethyldichlorosilane treatment is found to passivate the surface of TiN substrate, contrary to the generally accepted belief, when the TiN substrate is cleaned by $H_2O_2$ solution before the treatment.