Properties of local vibrational modes: the infrared intensity

2014 ◽  
pp. 149-163
Author(s):  
Wenli Zou ◽  
Dieter Cremer
Keyword(s):  
Vibrational Modes ◽  
Infrared Intensity ◽  
Local Vibrational Modes

High Energy Local Vibrational Modes of Carbon Aggregates in SiC: Experimental and Theoretical Insight

2006 ◽  
Vol 527-529 ◽  
pp. 465-468 ◽  
Author(s):  
Alexander Mattausch ◽  
M. Bockstedte ◽  
Oleg Pankratov ◽  
John W. Steeds ◽  
S.A. Furkert ◽  
...  
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
High Energy ◽  
Vibrational Modes ◽  
Energy Mode ◽  
Local Vibrational Modes ◽  
Theoretical Insight

We observe new photoluminescence centers in electron-irradiated 6H-SiC with phonon replicas up to 250 meV and clear threefold isotope splitting of the highest energy mode. Based on ab initio calculations, we discuss the tri-carbon anti-site (C3)Si and the di-interstitial (C2)Hex as models for these centers.

Local vibrational modes of H complexes in Mg-doped GaN grown by molecular beam epitaxy

2004 ◽  
Vol 84 (6) ◽  
pp. 897-899 ◽  
Author(s):  
R. Cuscó ◽  
L. Artús ◽  
D. Pastor ◽  
F. B. Naranjo ◽  
E. Calleja
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Vibrational Modes ◽  
Local Vibrational Modes ◽  
Mg Doped

Local vibrational modes of the Mg–H acceptor complex in GaN

1996 ◽  
Vol 69 (24) ◽  
pp. 3725-3727 ◽  
Author(s):  
W. Götz ◽  
N. M. Johnson ◽  
D. P. Bour ◽  
M. D. McCluskey ◽  
E. E. Haller
Keyword(s):  
Vibrational Modes ◽  
Acceptor Complex ◽  
Local Vibrational Modes

scholarly journals Raman and infrared studies ofLa1−ySryMn1−xMxO3(M=Cr, Co, Cu, Zn, Sc or Ga): Oxygen disorder and local vibrational modes

2006 ◽  
Vol 73 (22) ◽  
Author(s):  
A. Dubroka ◽  
J. Humlíček ◽  
M. V. Abrashev ◽  
Z. V. Popović ◽  
F. Sapiña ◽  
...  
Keyword(s):  
Vibrational Modes ◽  
Infrared Studies ◽  
Local Vibrational Modes

Local vibrational modes of the CuO4-cluster in ZnO

1996 ◽  
Vol 159 (1-4) ◽  
pp. 889-892 ◽  
Author(s):  
I. Broser ◽  
G. Kaczmarczyk ◽  
P. Thurian ◽  
R. Heitz ◽  
A. Hoffmann
Keyword(s):  
Vibrational Modes ◽  
Local Vibrational Modes

scholarly journals Local vibrational modes of vacancy-oxygen-related complexes at room temperature

2020 ◽  
Vol 56 (4) ◽  
pp. 480-487
Author(s):  
E. A. Tolkacheva ◽  
V. P. Markevich ◽  
L. I. Murin
Keyword(s):  
Absorption Band ◽  
Room Temperature ◽  
Clear Correlation ◽  
Ir Absorption ◽  
Oxygen Impurity ◽  
Interstitial Oxygen ◽  
Vibrational Modes ◽  
Oxygen Defect ◽  
Absorption Bands ◽  
Local Vibrational Modes

The isotopic content of natural silicon (28Si (92.23 %), 29Si (4.68 %) и 30Si (3.09 %)) affects noticeably the shape of IR absorption bands related to the oxygen impurity atoms. In the present work an attempt is undertaken to determine the positions of local vibrational modes (LVMs), related to quasimolecules 28Si16OS29Si and 28Si16OS30Si (OS – substitutional oxygen atom), for the absorption spectra measured at room temperature. An estimation of the isotopic shifts of corresponding modes is done by fitting the shape of the experimentally measured absorption band related to the vacancy–oxygen center in irradiated Si crystals. The LVM isotope shifts are found to be equal 2,2 ± 0.25 cm–1 for 28Si-16OS29Si and 4,3 ± 0,9 см–1 for 28Si-16OS30Si in relation to the basic band due to 28Si-16OS28Si, and the full width at half maximum of the A-center absorption band (28Si-16OS28Si) is 5,3 ± 0.25 cm–1. By means of infrared absorption spectroscopy a clear correlation between the disappearance of the divacancy (V2) in the temperature range 200–275 ºС and appearance of two absorption bands with their maxima at 825.8 and 839.2 cm–1 in irradiated oxygen-rich Si crystals is found. The band positioned at 825.8 cm–1 is assigned to a divacancy-oxygen defect V2O formed via an interaction of mobile V2 with interstitial oxygen (Oi ) atoms. The 839.2 cm–1 band is much more pronounced in neutron irradiated samples as compared to samples irradiated with electrons. We argue that it is related to a trivacancy–oxygen defect (V3O) formed via an interaction of mobile V3 with Oi atoms.

scholarly journals Многофононная релаксация состояний 1s(T-=SUB=-2-=/SUB=-) однократно ионизованного донора селена в кремнии

2020 ◽  
Vol 54 (9) ◽  
pp. 922
Author(s):  
Н.А. Бекин
Keyword(s):  
Luminescence Spectrum ◽  
Relaxation Rate ◽  
Wave Functions ◽  
Coupling Scheme ◽  
Published Data ◽  
Vibrational Modes ◽  
Fitting Procedure ◽  
Probability Of Transition ◽  
Local Vibrational Modes ◽  
Franck Condon

The rate of multiphonon relaxation of 1s(T2) level in Se+ donors in silicon was estimated. The calculation is an initial approach to the problem, which uses the most simplified form of wave functions. For the probability of transition, we used a well-known expression from the literature by R. Pässler [R. Pässler. Czech. J. Phys. B, 24, 322 (1974)], obtained in the framework of the so-called “static coupling scheme”. The deformation potentials of optical and acoustic phonons were determined by a fitting procedure using published data on the luminescence spectrum of Se+ donors at the 1s(T2) — 1s(A1) transition and the Franck-Condon principle. The resulting estimate for the relaxation rate, 103 s-1, was five orders of magnitude less than the rate corresponding to the experimentally measured lifetime. The reason for the discrepancy with the experiment is an oversimplified model that does not take into account several factors, the main of which is the presence of quasi-local vibrational modes. Analysis of the luminescence spectrum at this transition leads to the conclusion that the energies of such vibrational modes lie in the range from 26 to 61 meV. For a satisfactory agreement with the experiment, it is necessary to complicate the model, taking into account the interaction with these modes.

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