The Rayleigh phonon dispersion curve on Cu(100) in the direction

The MnNiCuSb Quaternary Heusler Alloy (QHA) in Y-type I stable structure (cubic) is studied for structural, elastic, mechanical and vibrational properties by using Density Functional Theory (DFT). Three independent elastic constants [Formula: see text], [Formula: see text] and [Formula: see text] for this cubic system are computed with Generalized Gradient Approximation (GGA) functional. The mechanical parameters like Young’s modulus, Shear and Bulk modulus, Pugh’s ratio, Poisson’s ratio, anisotropic factor, Cauchy pressure are then calculated by using these cubic elastic parameters. In addition, phonon dispersion curve and phonon density of states (PDOS) are computed with norm-conserving Martins–Troullier pseudo-potential in Perturbed Density Functional Theory. The phonon dispersion curve provides reststrahlen band 0.727 THz [Formula: see text] for which material behaves as 100%. This value corresponds to Far Infra-Red (FIR) spectral region so this alloy can be used for manufacturing FIR-devices.

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Effects of a weak intermediate-range attraction on the low-momentum part of the phonon dispersion curve in He II

Lettere al Nuovo Cimento ◽

10.1007/bf02733779 ◽

1973 ◽

Vol 7 (8) ◽

pp. 295-299 ◽

Cited By ~ 4

Author(s):

F. Iachello ◽

M. Rasetti

Keyword(s):

Dispersion Curve ◽

Phonon Dispersion ◽

Phonon Dispersion Curve ◽

Intermediate Range

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Structural, elastic, electronic and thermodynamic properties of ZrB2 under high-pressure: First-principle study

International Journal of Modern Physics B ◽

10.1142/s0217979218502004 ◽

2018 ◽

Vol 32 (16) ◽

pp. 1850200

Author(s):

Guo Zhang ◽

Yu-Xin Zhao ◽

Jun Zhu ◽

Yan-Jun Hao ◽

Lin Zhang

Keyword(s):

High Pressure ◽

High Temperature ◽

Thermodynamic Properties ◽

Dispersion Curve ◽

Phonon Dispersion ◽

Harmonic Approximation ◽

Optimization Method ◽

Hexagonal Structure ◽

Phonon Dispersion Curve ◽

Structure Stability

The structure of ZrB2 under high-pressure was predicted by Particle Swarm Optimization method (CALYPSO). We investigated the structure stability, phonon dispersion curve, elasticity, electronic structure and thermodynamic properties of ZrB2 under high-pressure and high-temperature via first-principles calculations. It maintained the hexagonal structure when the pressure lowers below 600 GPa at 0 K, which is confirmed by the calculated phonon dispersion curve. Studies indicate that the elastic modulus and Poisson’s ratio increase monotonically with pressure, as supported by some theoretical and experimental evidences. Calculated anisotropic factors demonstrate that compression and shear isotropy of ZrB2 weakens as the pressure increases. Using the quasi-harmonic approximation Debye model, the Debye temperature, sound velocity, expansion coefficient, thermal capacity under the high-temperature and pressure were also predicted.

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