• Title/Summary/Keyword: Structure-spectra correlation

Search Result 42, Processing Time 0.029 seconds

Expert System Approach for Vapor-Phase Infrared Spectra of Aromatic Compounds

  • Pyo Dongjin;Hwang Hoon;Lee Junyeoun
    • Bulletin of the Korean Chemical Society
    • /
    • v.13 no.2
    • /
    • pp.148-155
    • /
    • 1992
  • Computerized interpretation of vapor phase infrared spectra using a novel expert system approach for spectra/structure correlation for vapor phase spectra is introduced. Rapid identification of aromatic functional groups of components in gaseous mixture can be achieved using this expert system.

Annealing Effect with Various Ambient Conditions of ITO Thin Film (XPS와 XRD 분석을 이용한 ITO 박막의 결정성과 비정질 특성에 관한 연구)

  • Ko, Jung Whan;Jung, Bo Young;Oh, Teresa
    • Journal of the Semiconductor & Display Technology
    • /
    • v.14 no.4
    • /
    • pp.20-24
    • /
    • 2015
  • This study was explained the correlation between the O 1s spectra and the crystallization of ITO thin films. The crystal structure of ITO thin films changed with various annealing temperatures and annealing methods such as atmosphere or vaccum conditions. The amorphous structure observed from XRD pattern showed the O 1s spectra with 531.2 eV, and the crystal structure of annealed ITO films analyzed by XRD pattern had the O 1s spectra of 529.8 eV as lower binding energy then the 531.2 eV. Oxygen in view of ITO films was related to the crystallization, and the ITO films annealed in an atmosphere pressure showed higher crystal structure than the ITO annealed in a vaccum. It was indicated that the amorphous structure had higher binding energy than the crystal structure analyzed by O 1s spectra of ITO films.

2,4,6-Triamino-1,3,5-triazin-1-ium Acetate Acetic Acid Solvate Monohydrate. Infrared and Raman Spectra

  • Marchewka, M.K.
    • Bulletin of the Korean Chemical Society
    • /
    • v.25 no.4
    • /
    • pp.466-470
    • /
    • 2004
  • The crystals of the new melaminium salt, i.e. melaminium acetate acetic acid solvate monohydrate, $C_3H_7N_6^+ {\cdot}CH_3COO^- {\cdot}CH_3COOH{\cdot}H_2O$, were obtained by the slow evaporation of an aqueous solution at room temperature. Powder infrared and Raman spectra were measured and interpreted. The vibrational spectra in the region of internal vibrations of ions corroborate structural data recently published by Perpetuo and Janczak.$^1$ Some spectral features of this new crystal are referred to corresponding one for melamine crystal as well as other melamine complexes in crystalline form. Hydrogen-bonded network present in the crystal gives notable vibrational effect.

A Method for Selecting Ground Motions Considering Target Response Spectrum Mean, Variance and Correlation - I Algorithm (응답 스펙트럼의 평균과 분산, 상관관계를 모두 고려한 지반운동 선정 방법 - I 알고리즘)

  • Han, Sang Whan;Ha, Seong Jin;Cho, Sun Wook
    • Journal of the Earthquake Engineering Society of Korea
    • /
    • v.20 no.1
    • /
    • pp.55-62
    • /
    • 2016
  • It is important to select an accurate set of ground motions when conducting linear and nonlinear response history analyses of structures. This study proposes a method for selecting ground motions from a ground motion library with response spectra that match the target response spectrum mean, variance and correlation structures. This study also has addressed the determination of an appropriate value for the weight factor of a correlation structure. The proposed method is conceptually simple and straightforward, and does not involve a simulation algorithm. In this method, a desired number of ground motions are sequentially selected from first to last. The proposed method can be also used for selecting ground motions with response spectra that match the conditional spectrum. The accuracy and efficiency of the proposed procedure are verified with numerical examples.

Analysis of Crystallinity and Electrical Characteristics of Oxide Semiconductor of ZnO in Accordance with Annealing Methods (ZnO의 열처리방법에 따른 전기적인 특성의 변화와 결정성)

  • Oh, Teresa
    • Korean Journal of Materials Research
    • /
    • v.27 no.5
    • /
    • pp.242-247
    • /
    • 2017
  • ZnO film was prepared on a p-type Si wafer and then annealed at various temperatures in air and vacuum conditions to research the electrical properties and bonding structures during the annealing processes. ZnO film annealed in atmosphere formed a crystal structure owing to the suppression of oxygen vacancies: however, ZnO annealed in vacuum had an amorphous structure after annealing because of the increment of the content of oxygen vacancies. Schottky contact was observed for the ZnO annealed in an air. O 1s spectra with amorphous structure was found to have a value of 529 eV; that with a crystal structure was found to have a value of 531.5 eV. However, it was observed in these results that the correlation between the electronic characteristics and the bonding structures was weak.

Correlation Between Arrhenius Equation and Binding Energy by X-ray Photoelectron Spectroscopy

  • Oh, Teresa
    • Transactions on Electrical and Electronic Materials
    • /
    • v.14 no.6
    • /
    • pp.329-333
    • /
    • 2013
  • SiOC films were prepared by capacitively coupled plasma chemical vapor deposition, and the correlation between the binding energy by X-ray photoelectron spectroscopy and Arrhenius equation for ionization energy was studied. The ionization energy decreased with increase of the potential barrier, and then the dielectric constant also decreased. The binding energy decreased with increase of the potential barrier. The dielectric constant and electrical characteristic of SiOC film was obtained by Arrhenius equation. The dielectric constant of SiOC film was decreased by lowering the polarization, which was made from the recombination between opposite polar sites, and the dissociation energy during the deposition. The SiOC film with the lowest dielectric constant had a flat surface, which depended on how carbocations recombined with other broken bonds of precursor molecules, and it became a fine cross-linked structure with low ionization energy, which contributed to decreasing the binding energy by Si 2p, C 1s electron orbital spectra and O 1s electron orbital spectra. The dielectric constant after annealing decreased, owing to the extraction of the $H_2O$ group, and lowering of the polarity.

A Study on the Chemical Properties of AZO with Crystal Structure and IGZO of Amorphous Structure Due to the Annealing Temperature (결정질AZO 박막과 비정질IGZO 박막의 결정구조와 결합에너지와의 상관성)

  • So, Young Ho;Song, Jung Ho;Seo, Dong Myung;Oh, Teresa
    • Industry Promotion Research
    • /
    • v.1 no.1
    • /
    • pp.1-6
    • /
    • 2016
  • To research the correlation between the amorphous and crystal structure of oxide semiconductors, AZO and IGZO films were deposited and annealed with various temperatures in a vacuum state. AZO increased the degree of crystal structure with increasing the annealing temperature, but IGZO became an amorphous structure after the annealing process at high temperature. The series of AZO films with various annealing temperatures showed the chemical shift from the analyzer of PL and O 1s spectra, but the results of IGZO films by PL and O 1s spectra were not observed the chemical shift. The binding energy of oxygen vacancy of AZO with a crystal structure was 531.5 eV, and that of IGZO with an amorphous structure was 530 eV as a lower binding energy.

Ab-initio Calculations of Mg Silicate and (hydr)oxide Core-level Absorption Spectra (Mg 규산염 및 (수)산화물에 대한 제일원리 내각준위 흡수 스펙트럼 계산 연구)

  • Son, Sangbo;Kwon, Kideok D.
    • Korean Journal of Mineralogy and Petrology
    • /
    • v.34 no.2
    • /
    • pp.121-131
    • /
    • 2021
  • Magnesium (Mg) present in carbonate minerals as impurities has been used as a geochemical proxy to infer the environmental conditions where the minerals precipitated. The reliability of Mg geochemical proxies requires fundamental understanding of Mg incorporation into minerals based on accurate speciation of Mg 2+ in the crystal structure, which is determined mainly by application of X-ray absorption spectroscopy (XAS). However, high uncertainties are involved in interpreting the XAS spectra of minerals containing trace amount of Mg 2+. Because density function theory (DFT) can predict an XAS spectrum for a crystal structure, DFT calculations can reduce the uncertainties in the interpretation of the XAS spectrum. In this study, we calculated ab initio Mg K-edge absorption spectra of Mg silicates and (hydr)oxides based on DFT and analyzed the correlation between the calculated spectra and Mg structural parameters. Our ab initio Mg K-edge absorption spectra well reproduced the key features of the experimental spectra. The absorption-edge positions of the calculated spectra showed the weak positive correlation with the average Mg-O bond distance or Mg effective coordination number. The current study shows that DFT-based core-level spectroscopy method is a powerful tool in providing standard Mg K-edge spectra of diverse Mg minerals and determining the Mg chemical species within carbonate minerals.

Correlation between Chemical Shift and Optical Properties and of SiOC Films (탄소주입 실리콘 산화막 박막의 광학적 특성과 화학적 이동의 상관성)

  • Oh, Teresa
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.13 no.3
    • /
    • pp.1279-1283
    • /
    • 2012
  • SiOC films made by the inductive coupled CVD with dimethyldimethoxysilane were analyzed to find out the correlation between the chemical and optical properties by using the Foruier transform infrared spectroscopy, spectrophotometer and ellipsometer. The bonding structure of SiOC film was formed during the depositeion and the adhesion was increased after annealing process. SiOC film decreased the polarization by the chemical reaction between alkyl group and hydroxyl group, and increased the degree of amorphism. For the range of 950 cm-1 in FTIR spectra, the spectra were divided into two types depending on polar sites. The refractive index of SiOC film with the lowest polarization increased and the thickness of that decreased.