Lattice dynamics and inelastic neutron scattering from forsterite, Mg2SiO4: Phonon dispersion relation, density of states and specific heat

1988 ◽  
Vol 16 (1) ◽  
Author(s):  
K.R. Rao ◽  
S.L. Chaplot ◽  
Narayani Choudhury ◽  
Subrata Ghose ◽  
J.M. Hastings ◽  
...  
Keyword(s):  
Dispersion Relation ◽  
Neutron Scattering ◽  
Specific Heat ◽  
Density Of States ◽  
Lattice Dynamics ◽  
Phonon Dispersion ◽  
Inelastic Neutron Scattering ◽  
Inelastic Neutron ◽  
Phonon Dispersion Relation

Lattice dynamics of white tin

1967 ◽  
Vol 300 (1460) ◽  
pp. 25-44 ◽  
Keyword(s):  
Lattice Dynamics ◽  
Phonon Dispersion ◽  
Inelastic Neutron Scattering ◽  
Dominant Role ◽  
Theoretical Work ◽  
Inelastic Neutron ◽  
Conduction Electrons ◽  
Phonon Dispersion Relation ◽  
Scattering Measurements ◽  
Made In

The phonon dispersion relation of white tin has been studied with the technique of inelastic neutron scattering. Measurements were made in the (001) and (010) planes, on both a time-of-flight apparatus and a triple-axis spectrometer. Results are given along the symmetry directions. A force-constant model has been used to interpret the experimental measurements. Other theoretical work is discussed, and comparison is made of these results with superconducting tunnelling measurements. There are features in the observed dispersion curves suggesting that, as in lead, the interactions with the conduction electrons play a dominant role.

scholarly journals Study of Anharmonicity in Zirconium Hydrides Using Inelastic Neutron Scattering and Ab-Initio Computer Modeling

Inorganics ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 29
Author(s):  
Jiayong Zhang ◽  
Yongqiang Cheng ◽  
Alexander I. Kolesnikov ◽  
Jerry Bernholc ◽  
Wenchang Lu ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Excited States ◽  
Lattice Dynamics ◽  
Density Functional ◽  
Inelastic Neutron Scattering ◽  
Inelastic Neutron ◽  
Vibrational States ◽  
Functional Theory ◽  
Hydrogen Deuterium ◽  
Zirconium Hydrides

The anharmonic phonon behavior in zirconium hydrides and deuterides, including ϵ-ZrH2, γ-ZrH, and γ-ZrD, has been investigated from aspects of inelastic neutron scattering (INS) and lattice dynamics calculations within the framework of density functional theory (DFT). The harmonic model failed to reproduce the spectral features observed in the experimental data, indicating the existence of anharmonicity in those materials and the necessity of further explanations. Here, we present a detailed study on the anharmonicity in zirconium hydrides/deuterides by exploring the 2D potential energy surface of hydrogen/deuterium atoms and solving the corresponding 2D single-particle Schrödinger equation to obtain the eigenfrequencies, which are then convoluted with the instrument resolution. The convoluted INS spectra qualitatively describe the anharmonic peaks in the experimental INS spectra and demonstrate that the anharmonicity originates from the deviations of hydrogen potentials from quadratic behavior in certain directions; the effects are apparent for the higher-order excited vibrational states, but small for the ground and first excited states.

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