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.

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.

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.

Measurement of Anomalous Phonon Dispersion ofCaFe2As2Single Crystals Using Inelastic Neutron Scattering

2009 ◽  
Vol 102 (21) ◽  
Author(s):  
R. Mittal ◽  
L. Pintschovius ◽  
D. Lamago ◽  
R. Heid ◽  
K-P. Bohnen ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Phonon Dispersion ◽  
Inelastic Neutron Scattering ◽  
Inelastic Neutron
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