scholarly journals Far-infrared absorption in cubic ZnS

1976 ◽  
Vol 54 (10) ◽  
pp. 1053-1060 ◽  
Author(s):  
E. A. Kwasniewski ◽  
E. S. Koteles ◽  
W. R. Datars
Keyword(s):  
Absorption Spectrum ◽  
Infrared Absorption ◽  
Phonon Dispersion ◽  
Far Infrared ◽  
Fourier Transform Spectrometer ◽  
High Symmetry ◽  
Phonon Density ◽  
Zone Boundary ◽  
Phonon Density Of States ◽  
Phonon Dispersion Curves

Far-infrared absorption in cubic ZnS due to single-phonon and two-phonon processes was measured with a high resolution, far-infrared Fourier transform spectrometer. A 14-parameter lattice dynamical shell model was fitted to phonon dispersion curves measured by Vagelatos et al. The two-phonon density-of-states calculated with these parameters was compared with the absorption spectrum. Two-phonon combinations and their locations in the Brillouin zone were identified with features of the absorption spectrum. Critical points were found on or near the zone boundary and not only at high symmetry points as suggested previously.

Far-infrared absorption in CdTe

1977 ◽  
Vol 55 (22) ◽  
pp. 2013-2018 ◽  
Author(s):  
E. Batalla ◽  
E. S. Koteles ◽  
W. R. Datars
Keyword(s):  
Absorption Spectrum ◽  
Brillouin Zone ◽  
Infrared Absorption ◽  
Far Infrared ◽  
High Accuracy ◽  
Compound Semiconductor ◽  
Model Parameters ◽  
Fourier Transform Spectrometer ◽  
Phonon Density ◽  
Phonon Density Of States

Far-infrared absorption in the II–VI compound semiconductor Cd Te has been measured using a Fourier transform spectrometer. Two-phonon density-of-states curves were calculated from shell model parameters determined by Rowe, Nicklow, Price, and Zanio and were compared to the high-accuracy absorption spectrum. Two-phonon combinations and the location of the corresponding critical points in the Brillouin zone were identified with features in the absorption spectrum. From these assignments, accurate values of some normal mode frequencies at certain points in the Brillouin zone were determined.

Two-phonon absorption in InSb, InAs, and GaAs

1976 ◽  
Vol 54 (16) ◽  
pp. 1676-1682 ◽  
Author(s):  
E. S. Koteles ◽  
W. R. Datars
Keyword(s):  
Phonon Dispersion ◽  
Inelastic Neutron Scattering ◽  
Far Infrared ◽  
Inelastic Neutron ◽  
Model Fit ◽  
Fourier Transform Spectrometer ◽  
Phonon Density ◽  
Phonon Dispersion Curves ◽  
Phonon Absorption ◽  
Good Agreement

Far-infrared absorption in the III–V compound semiconductors InSb, InAs, and GaAs has been measured using a Fourier transform spectrometer. The high-resolution spectra of the three materials were found to be very similar. Features on the spectra were assigned to two-phonon sum and difference processes with the aid of two-phonon density-of-states curves for InSb and GaAs calculated from a shell model fit to phonon dispersion curves. Interpretation of the spectrum of InAs was possible because of its similarity to that of InSb and GaAs. The frequencies of phonons at certain points in the Brillouin zone of InSb and GaAs determined from the mode assignments to the infrared spectra were in good agreement with previous measurements by inelastic neutron scattering and Raman scattering.

LATTICE DYNAMICS OF MBa2Cu3O7(M=Y, Gd) and YBa2Cu3O6

1989 ◽  
Vol 03 (08) ◽  
pp. 1277-1286 ◽  
Author(s):  
JIE QIN ◽  
YIMIN JIANG
Keyword(s):  
Density Of States ◽  
Phonon Dispersion ◽  
Experimental Investigations ◽  
Phonon Density ◽  
Phonon Density Of States ◽  
Phonon Dispersion Curves ◽  
Rare Earth Atom ◽  
Range Overlap ◽  
Phonon Properties ◽  
Good Agreement

We have presented a lattice dynamical calculation of phonon dispersion curves and one-phonon density of states for the high-T c superconducting MBa 2 Cu 3 O x (M=Y, Gd : x=7, 6) compounds. The model we used is in the framework of a rigid-ion model which includes long-range Coulomb potential and a short-range overlap. The results of calculation give quite good agreement with the available Raman and infrared data, and the measurements of phonon density of states. These results therefore can serve as a guide for further experimental investigations of the phonon properties in M-Ba-Cu-O (M=rare earth atom) system.

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