• Bulletin of the Korean Chemical Society
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• v.21 no.10
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• pp.1035-1038
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• 2000

Vibrational properties of dopamine neutral species in powder state have been studied by means of the normal mode analysis based on the force constants obtained from the density functional calculation at B3LYP level and the results of Fourier trans form Raman and infrared spectroscopic measurements. Ab initio calculation at MP2 level shows that the trans conformer of dopamine has higher electronic energy about 1.4 kcal/mol than those of the gauche+ and the gauche-conformers, and two gauche conformers have almost the same energies. Free energies calculated at HF and B3LYP levels show very similar values for three conformers within 0.3 kcal/mol. Empirical force field has been constructed from force constants of three conformers, and refined upon ex-perimental Raman spectrum of dopamine to rigorous values. The major species of dopamine neutral base in the powder state is considered a trans conformer as shown in the crystallographic study of dopamine cationic salt.

• Journal of the Korean Chemical Society
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• v.30 no.2
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• pp.152-158
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• 1986

The dissociation constants of 4-Cl-1-naphthol, 6-Br-2-naphthol and $8-NH_2-2-naphthol$ in aqueous solution were measured by spectroscopic method in the temperature range from 25 to 40${\circ}C$ and pressure up to 2000bar. The dissociation constants were decreased as the substituents were inserted in naphthol f rom $4.4{\times}10^{-10}\;to\;5.82{\times}10^{-11}$ as chloride compound and $2.5{\times}10^{-10}\;to\;3.44{\times}10^{-11}\;or\;4.21{\times}10^{-11}$ as bromine or amino compounds, respectively. This decrease can be explained with the I-or R-effects of substituents. From the dissociation constants various thermodynamic properties were calculated and discussed the characteristics of the dissociation reaction.

• Journal of Environmental Science International
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• v.5 no.6
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• pp.757-762
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• 1996

The removal effectiveness of various heavy metal ions in boron-rich containing plants has been studied by means of spectroscopic and pH methods. Treatment of the boron-rich containing sample which was collected from cherry and root of cabbage to heavy metal ions is resulted in that an excellent removal effect shows in the case of large ionic size of heavy metal. Stability constants are depended on the variation of pH.

• Proceedings of the Optical Society of Korea Conference
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• 2001.02a
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• pp.264-265
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• 2001

영상표시방법은 관례적인 CRT 방법에 더하여 LCD, TFT-LCD, FED, PDP 등 다양한 방법들이 개발되었거나 개발되고 있다. 유기발광소자(OLED)를 이용한 영상표시법도 최근 그 실용성이 크게 향상된 방법으로 이 OLED를 이용하는 발광소자는 LCD, TFT-LCD 등의 방법과 마찬가지로 다층박막구조를 가지므로 각 박막층의 특성과 계면 급준성 등을 정확하게 평가하는 것은 긴요하다 하겠다. (중략)

• Bulletin of the Korean Chemical Society
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• v.11 no.1
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• pp.34-41
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• 1990

The second order ab initio effective valence shell Hamiltonian is calculated for the valence state potential energy curves of NH and $NH^+$. From the potential energy curves various spectroscopic constants of valence states are determined. The results are in good agreement with experiments and configuration interaction calculations. They show the composite picture of potential energy curves and also indicate that the second order effective Hamiltonian theory is adequate for describing various valence states of a molecule and its ions simultaneously.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.3
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• pp.77-81
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• 2007

We sputtered $TiN_x$ (titanium nitride) thin films on silicon substrates using ultra high vacuum RF magnetron sputtering method, and measured spectra of ellipsometry angles ${\Delta}$ and ${\Psi}$ in the photon-energy range of 1.5-5.0 eV using a variable angle spectroscopic ellipsometer. The optical constants, refractive index and extinction coefficient of the $TiN_x$ films were determined via the dispersion parameters extracted from the curve-fitting process based on Drude+Lorentz oscillator dispersion function. The reliability of determined optical constants were verified through the comparison of between simulated reflectance and reflectance spectra measured using a spectrophotometer.

• Journal of the Korean Magnetics Society
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• v.5 no.5
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• pp.496-499
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• 1995

Amorphous $Co_{80+x}TM_{12}B_{8-x}$ (TM = Ti, Zr, Hf, Nb and x = 0, 2, 4 at%) alloys were prepared by single roll melt spinning technique. Saturation magnetization of the amorphous ribbons was measured by SQUID and vibrating sample magnetometer from 5 to 800 K under applied fields up to 10 kOe. Typical thermo-magnetization curves were observed and the average values of the spectroscopic splitting g factor were estimated from the ferromagnetic resonance curve. For all the amorphous alloys studied here the saturation magnetization in the temperature range 5 K up to about $0.3T_{c}$ can be described by the Bloch relation: $M_{s}(T)\;=\;M_{s}(0)(1-BT^{3/2}-CT^{5/2})$. From the values of $M_{s}(0)$, B and spectroscopic splitting g factor the spin wave stiffness constants were calculated.

• Journal of the Korean Vacuum Society
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• v.16 no.2
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• pp.134-140
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• 2007

Optical structure of $V_{2}O_{5}$ thin films were analyzed and confirmed, the films were deposited in oxygen partial pressure 0% and 10% by RF magnetron sputtering system. Measurements of the elliptic constants were made in the range of $0.75{\sim}4.0\;eV$ by using phase modulated spectroscopic ellipsometer. The elliptic constants of the thin films were analyze by Double Amorphous dispersion relation. The calculated n, k spectra of $V_{2}O_{5}$ layer were obtained over the range of $0.75{\sim}4.0\;eV$ photon energy. SEM and XRD measurements were also made to validate the ellipsometric analysis and they give good agreement with the structural properties of the films. It was found that optical structure of the $V_{2}O_{5}$ layer has a 3 phase(roughness/film/substrate) and optical absorption properties are greatly depend on the partial pressure of the oxygen.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.361-361
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• 2012

PZT (Pb(Zr,Ti)O3) thin films have been used widely in the MEMS application, due to their inherent ferroelectric and piezoelectric properties. Such ferroelectricity induces much higher dielectric constants compared to those of the nonperovskite materials. In this work, the PZT thin films were deposited onto Indium-Tin-oxide (ITO) substrates through the spin-coating of PZT sols. The deposited PZT thin films were characterized in terms of the electrical and optical properties with special emphases on conductivity and optical constants. The detailed analysis techniques incorporate the dc-based current-voltage characteristics for the electrical properties, spectroscopic ellipsometry for optical characterization, atomic force microscopy for surface morphology, X-ray Photoelectron Spectroscopy for chemical bonding, Energy-dispersive X-ray Spectrometry for chemical analyses and X-ray diffraction for crystallinity. The ferroelectric phenomena were confirmed using capacitance-voltage measurements. The integrated physical/chemical features are attempted towards energy-oriented applications applicable to next-generation high-efficiency power generation systems.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.3
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• pp.228-233
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• 2010

We studied the optical characteristics correlated with low dielectric constants of low-k SiOCH thin films through ellipsometry. The low-k SiOCH thin films were prepared by CCP-PECVD method using BTMSM(Bis-trimethylsilylmethane) precursors deposited on p-Si wafer. The Si-O-CHx, Si-O-Si, Si-CHx, CHx and Si-H bonding groups were specified by FTIR spectroscopic spectra, and the groups coupled with the nano-porous structural organic/inorganic hybrid-type of SiOCH thin films which has extremely low dielectric constant close to 2.0. The structural groups includes highly dense pore as well as ions in SiOCH thin films affecting to complex refraction characteristics of single layer on the p-Si wafer. The structural complexity originate the complex refractive constants of the films, and resulted the elliptical polarization of the incident linearly polarized light source of Xe-light source in the range from 190 nm to 2100 nm. Phase difference and amplitude ratio between s wave and p wave propagating through SiOCH thin film was studied. After annealing, the amplitude of p wave was reduced more than s wave, and phase difference between p and s wave was also reduced.