scholarly journals Large phonon band gap inSrTiO3and the vibrational signatures of ferroelectricity inATiO3perovskites: First-principles lattice dynamics and inelastic neutron scattering

2008 ◽  
Vol 77 (13) ◽  
Author(s):  
Narayani Choudhury ◽  
Eric J. Walter ◽  
Alexander I. Kolesnikov ◽  
Chun-Keung Loong
Keyword(s):  
Neutron Scattering ◽  
Band Gap ◽  
First Principles ◽  
Lattice Dynamics ◽  
Inelastic Neutron Scattering ◽  
Inelastic Neutron ◽  
Phonon Band

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.

Lattice dynamics and inelastic neutron scattering from sillimanite and kyaniteAl2SiO5

1999 ◽  
Vol 60 (17) ◽  
pp. 12061-12068 ◽  
Author(s):  
Mala N. Rao ◽  
S. L. Chaplot ◽  
Narayani Choudhury ◽  
K. R. Rao ◽  
R. T. Azuah ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Lattice Dynamics ◽  
Inelastic Neutron Scattering ◽  
Inelastic Neutron

Inelastic neutron scattering and lattice dynamics of minerals

2002 ◽  
Vol 14 (2) ◽  
pp. 291-329 ◽  
Author(s):  
Samrath L. Chaplot ◽  
Narayani Choudhury ◽  
Subrata Ghose ◽  
Mala N. Rao ◽  
Ranjan Mittal ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Lattice Dynamics ◽  
Inelastic Neutron Scattering ◽  
Inelastic Neutron

scholarly journals On the microscopic dynamics of the ‘Einstein solids’ AlV2Al20 and GaV2Al20, and of YV2Al20: a benchmark system for ‘rattling’ excitations

2015 ◽  
Vol 17 (38) ◽  
pp. 24837-24850 ◽  
Author(s):  
Michael Marek Koza ◽  
Hannu Mutka ◽  
Yoshihiko Okamoto ◽  
Jun-ichi Yamaura ◽  
Zenji Hiroi
Keyword(s):  
Density Functional Theory ◽  
High Resolution ◽  
Neutron Scattering ◽  
Lattice Dynamics ◽  
Density Functional ◽  
Inelastic Neutron Scattering ◽  
Inelastic Neutron ◽  
Functional Theory ◽  
Inelastic Response ◽  
Benchmark System

The inelastic response of AV2Al20 (with A = Al, Ga and Y) was probed by high-resolution inelastic neutron scattering experiments and density functional theory (DFT) based lattice dynamics calculations (LDC).

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