scholarly journals Оптические свойства фазопеременных материалов системы германий--сурьма-теллур составов Ge-=SUB=-14-=/SUB=-Sb-=SUB=-29-=/SUB=-Te-=SUB=-57-=/SUB=- и Ge-=SUB=-15-=/SUB=-Sb-=SUB=-15-=/SUB=-Te-=SUB=-70-=/SUB=- в дальнем инфракрасном диапазоне

2021 ◽  
Vol 55 (7) ◽  
pp. 542
Author(s):  
В.А. Рыжов ◽  
Б.Т. Мелех ◽  
Л.П. Казакова
Keyword(s):  
Amorphous Alloy ◽  
Infrared Absorption ◽  
Crystalline State ◽  
Room Temperature ◽  
Torsional Vibrations ◽  
Phonon Modes ◽  
Absorption Bands ◽  
Structural Units ◽  
Chalcogenide Alloys ◽  
Infrared Absorption Spectra

Abstract Infrared absorption spectra of chalcogenide alloys of the GST system with the compositions Ge14Sb29Te57 and Ge15Sb15Te70 in the amorphous and crystalline state were measured and analyzed in the range of 20 – 400 cm– 1 (0.6 – 12 THz) at room temperature. Absorption at these frequencies is due to the manifestation of correlated torsional vibrations of structural units of the amorphous alloy and phonon modes of the crystal. The performed assignment of absorption bands and the revealed differences in the IR spectra make it possible to more confidently represent the possible molecular mechanism of reversible amorphous-crystalline transformations in the studied phase-changing materials

Infrared Absorption Spectra and Their Correlation with the Ti-O Bond Length Variations for TiO2 (Rutile), Na-Titanates, and Na-Titanosilicate (Natisite, Na2TiOSiO4)

1995 ◽  
Vol 49 (11) ◽  
pp. 1646-1651 ◽  
Author(s):  
Gow-Weng Peng ◽  
Shou-Kang Chen ◽  
Hok-Shing Liu
Keyword(s):  
Bond Length ◽  
Absorption Spectra ◽  
Infrared Absorption ◽  
Ir Absorption ◽  
Crystalline Solids ◽  
Absorption Bands ◽  
Structural Units ◽  
Structure Correlations ◽  
Geometric Setting ◽  
Infrared Absorption Spectra

The mid-infrared absorption spectra (400–1200 cm−1) of four TiO2-bearing crystalline solids, in the form of rutile (TiO2), Na-titanates (Na2Ti6O13/ Na2Ti3O7), and natisite (Na2TiOSiO4), are presented, providing a clear illustration of their differences in IR band structure (band pattern). Two sharp characteristic peaks of IR absorption bands of natisite have been noted at 725 and 624 cm−1, representing the internal vibration modes of TiO5 (normal) and SiO4 structural units, respectively, and obtainable by comparison with that of Ca-titanosilicate (CaTiOSiO4), NTS glass (Na2O-TiO2-SiO2), and low-cristobalite (SiO2). The tested series of TiO2-bearing crystalline solids has been helpful in presenting a case study in support for the generalization of IR spectra/structure correlations, showing that vibrational spectroscopy can be useful for understanding the crystal chemistry of crystalline solids in terms of the geometric setting of molecular structural units and chemical bonds. It has been qualitatively demonstrated that the Ti-O bond length variations may be broadly correlated with the complexity of IR absorption bands of four TiO2-bearing solids having great diversity in both chemical composition and crystalline structure.

Deuteron Magnetic Resonance and Infrared Absorption Studies of Structure and Dynamics in Amorphous Hydrogenated Carbon and Carbon Nitride

1994 ◽  
Vol 349 ◽  
Author(s):  
Shu-Han Lin ◽  
Bernard J. Feldman ◽  
J. R. Bodart ◽  
V. P. Bork ◽  
M. J. Kernan ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Absorption Spectra ◽  
Infrared Absorption ◽  
Carbon Nitride ◽  
Room Temperature ◽  
Absorption Studies ◽  
Nitrogen Concentrations ◽  
Infrared Absorption Spectra ◽  
Bending Modes ◽  
Amorphous Hydrogenated Carbon

ABSTRACTDeuteron magnetic resonance (DMR) and infrared absorption spectra have been measured in amorphous hydrogenated carbon (a-C:H and a-C:D,H) and amorphous hydrogenated carbon nitride (a-CN:D,H) films plasma-deposited onto room-temperature substrates from feedstock mixtures of CH4, N2, and D2. DMR spectra and transient magnetization recoveries were measured between room temperature and 4 K. Recoveries are dominated by magnetization transport under extreme inhomogeneity. Methyl rotors CDx H3-x freeze out below 77 K. From the infrared absorption spectra, NH2, CHx, double bonded C-C, and triple bonded C-N stretching modes are observed. As a function of increasing nitrogen concentrations, the NH2 and C-N intensities dramatically increase while the CHx and C-C intensities decrease. In films where the ratio of nitrogen to carbon plus nitrogen is greater than 25%, the absorption spectra are dominated by NH2 stretching and bending modes; in contrast, the DMR spectra show many CDxHy configurations and a broader NDxHy structure. Proton NMR shows significant hydrogen clustering in a-CN:D,H.

A theory of the broadening of the infrared absorption spectra of hydrogen-bonded species. I

1974 ◽  
Vol 337 (1609) ◽  
pp. 167-197 ◽  
Keyword(s):  
Infrared Absorption ◽  
Formal Method ◽  
Subsequent Paper ◽  
Complex Energy ◽  
Vibrational States ◽  
Absorption Bands ◽  
Vibrational Predissociation ◽  
Energy Eigenvalues ◽  
Infrared Absorption Spectra ◽  
Hydrogen Bonded

A theory of the intramolecular contributions to the broadening of the v (XH) absorption bands of hydrogen-bonded species is proposed, which is able to describe both vibrational predissociation and the formation of sum and difference bands. A formal method is developed for finding the wavefunctions and complex energy eigenvalues of quasi-stationary excited vibrational states of a linear triatomic system with realistic interactions. The theory is applied to the Me 2 O.HCl system. It is found that predissociation broadening is negligible. The calculation of combination band intensities, and of the spread in energy of terms within such bands, will be reported in a subsequent paper.

scholarly journals Calibrations coefficients for determination of concentrations of vacancy-oxygen-related complexes and oxygen dimer in silicon by means of infrared absorption spectroscopy

2021 ◽  
Vol 66 (2) ◽  
pp. 227-233
Author(s):  
I. F. Medvedeva ◽  
V. P. Markevich ◽  
K. A. Talkachova ◽  
A. A. Fadzeyeva ◽  
D. N. Zhdanovich ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Infrared Absorption ◽  
Room Temperature ◽  
Crystalline Silicon ◽  
Calibration Coefficient ◽  
Ir Absorption ◽  
Absorption Bands ◽  
Oxygen Precipitates ◽  
Calibration Coefficients

Vacancy-oxygen complexes VnOm (n, m ≥ 1) in crystalline silicon are nucleation centers for oxygen precipitates, which are widely used as internal getters in modern technologies of production of silicon-based electronic devices and integrated circuits. For the controllable formation of oxygen precipitates in Si crystals in the technology processes the methods of determination of concentrations of the VnOm complexes are required. The aim of the present work was to find values of the calibration coefficients for determination of concentrations of the VnOm defects in Si from intensities of infrared (IR) absorption bands associated with the local vibrational modes (LVM) of these complexes. A combined electrical (Hall effect) and optical (IR absorption) study of vacancy-oxygen defects in identical silicon crystals irradiated with 6 MeV electrons was carried out. Based on the analysis of the data obtained, the values of the calibration coefficient for the determination of concentration of the vacancy-oxygen (VO) complex in silicon by the infrared absorption method were established: for measurements at room temperature (RT) – NVO = 8.5 · 1016 · αVO-RT cm–3, in the case of low-temperature (LT, Т ≡ 10 K) measurements – NVO = 3.5 · 1016 · αVO-LT cm–3, where αVO-RT(LT) are absorption coefficients in maxima of the LVM bands due to the VO complex in the spectra measured at corresponding temperatures. Calibration coefficients for the determination of concentrations of other VnOm (VO2, VO3, VO4, V2O and V3O) complexes and the oxygen dimer (O2) from an analysis of infrared absorption spectra measured at room temperature have been also determined.

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