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.

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.

Phonon renormalization of the electronic effective mass

1969 ◽  
Vol 47 (10) ◽  
pp. 1107-1116 ◽  
Author(s):  
J. P. Carbotte ◽  
R. C. Dynes ◽  
P. N. Trofimenkoff
Keyword(s):  
Effective Mass ◽  
Phonon Dispersion ◽  
Inelastic Neutron Scattering ◽  
Inelastic Neutron ◽  
Force Constants ◽  
Coupling Constant ◽  
Phonon Dispersion Curves ◽  
Electron Phonon Interaction ◽  
Phonon Renormalization ◽  
Pseudo Potential

We have made detailed first principle calculations of the phonon contribution to the renormalization of the electronic effective mass of a number of simple metals and alloys. The phonon frequencies and polarization vectors are generated from the interatomic force constants for the material. The force constants are taken from a Born – von Kármán analysis of the experimental phonon dispersion curves determined by inelastic neutron scattering. The electron–phonon interaction is treated using pseudo-potential theory which relates the coupling constant to the electron–ion form factor. For a spherical Fermi surface it is then possible to evaluate numerically the expression for the effective mass with no further approximations. We compare the results obtained with previous work when available and with experiment otherwise.

Phonon dispersion curves by inelastic neutron scattering to 12 Gpa

2001 ◽  
Vol 216 (8) ◽  
Author(s):  
S. Klotz
Keyword(s):  
Neutron Scattering ◽  
Phonon Dispersion ◽  
Inelastic Neutron Scattering ◽  
Ambient Pressure ◽  
Inelastic Neutron ◽  
Dispersion Curves ◽  
Stability Range ◽  
Phonon Dispersion Curves ◽  
Simple Systems ◽  
Considerable Detail

AbstractRecent progress in high pressure techniques allows the measurements of phonon dispersion curves to ~12 GPa by inelastic neutron scattering on triple axis spec-trometers. Provided the structure is not too complex, a vari-ety of low-compressibility solids may be studied over the entire stability range of their ambient pressure forms. This article reviews results obtained during the last five years on the lattice dynamics of a number of “simple” systems (Ge, GaSb, PbTe, FeO, Zn, Fe) where the pressure-induced frequency shifts of the acoustic branches have been studied in considerable detail. In several of these solids pronounced “mode softening” is found under pressure. Grüneisen parameters and elastic constants have been determined and the results were compared to predictions of first-principle calculations.

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.

scholarly journals Phonon Dispersion Relations for Chromium and Tantalum

1975 ◽  
Vol 28 (1) ◽  
pp. 57 ◽  
Author(s):  
Jyoti Prakash ◽  
LP Pathak ◽  
MP Hemkar
Keyword(s):  
Force Constant ◽  
Phonon Dispersion ◽  
Normal Modes ◽  
Inelastic Neutron ◽  
Neutron Spectroscopy ◽  
Phonon Dispersion Curves ◽  
Modes Of Vibration ◽  
Experimental Values ◽  
Good Agreement ◽  
Phonon Dispersion Relations

Phonon dispersion curves for the normal modes of vibration in chromium and tantalum are calculated along the symmetry directions [100], [110] and [111] using the five force-constant model of Behari and Tripathi (1970a). The results are compared with experimental values obtained from inelastic neutron spectroscopy and reasonably good agreement is found.

Angular Forces and Normal Vibrations in Platinum

1977 ◽  
Vol 32 (12) ◽  
pp. 1490-1494
Author(s):  
H. L. Kharoo ◽  
O. P. Gupta ◽  
M. P. Hemkar
Keyword(s):  
Phonon Dispersion ◽  
Inelastic Neutron Scattering ◽  
Sampling Technique ◽  
Inelastic Neutron ◽  
Dynamical Study ◽  
Normal Vibrations ◽  
Specific Heats ◽  
Debye Temperatures ◽  
Root Sampling ◽  
Good Agreement

Abstract A lattice dynamical study of platinum has been made on the basis of the improved Clark-Gazis-Wallis model considering volume forces of Krebs' nature. The phonon dispersion relations obtained for the three symmetry directions have been compared with the recent inelastic neutron scattering experiments. The specific heat at constant volume has been calculated by Blackman's root sampling technique for temperatures above Θ/10, and below this temperature the calculations are carried out by employing the modified Houston spherical six-term integration procedure. The computed lattice specific heats in terms of the effective Debye temperatures Θ are compared with the available calorimetric data. The theory is in good agreement with the experimental data.

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