scholarly journals Strong anharmonicity in the phonon spectra of PbTe and SnTe from first principles

2018 ◽  
Vol 97 (1) ◽  
Author(s):  
Guilherme A. S. Ribeiro ◽  
Lorenzo Paulatto ◽  
Raffaello Bianco ◽  
Ion Errea ◽  
Francesco Mauri ◽  
...  
Keyword(s):  
First Principles ◽  
Phonon Spectra ◽  
Strong Anharmonicity

FIRST PRINCIPLES CALCULATION OF THE PHONON SPECTRA OF SOLIDS

1981 ◽  
Vol 42 (C6) ◽  
pp. C6-625-C6-627 ◽  
Author(s):  
P. E. Van Camp ◽  
V. E. Van Doren ◽  
J. T. Devreese
Keyword(s):  
First Principles ◽  
First Principles Calculation ◽  
Phonon Spectra

New Pt-based Superalloy System Designed from First Principles

2008 ◽  
Vol 1128 ◽  
Author(s):  
Vsevolod I. Razumovskiy ◽  
Eyvaz I. Isaev ◽  
Andrei V. Ruban ◽  
Pavel A. Korzhavyi
Keyword(s):  
Elastic Properties ◽  
First Principles ◽  
Defect Formation ◽  
Alloy System ◽  
First Principles Calculations ◽  
Phonon Spectra ◽  
Ultrahigh Temperature ◽  
New Generation ◽  
Formation Energies ◽  
Temperature Applications

AbstractPt-Sc alloys with the γ-γ′ microstructure are proposed as a basis for a new generation of Pt-based superalloys for ultrahigh-temperature applications. This alloy system was identified on the basis of first-principles calculations. Here we discuss the prospects of the Pt-Sc alloy system on the basis of calculated elastic properties, phonon spectra, and defect formation energies.

scholarly journals Strong anharmonicity and high thermoelectric efficiency in high-temperature SnS from first principles

2019 ◽  
Vol 100 (21) ◽  
Author(s):  
Unai Aseginolaza ◽  
Raffaello Bianco ◽  
Lorenzo Monacelli ◽  
Lorenzo Paulatto ◽  
Matteo Calandra ◽  
...  
Keyword(s):  
High Temperature ◽  
First Principles ◽  
Thermoelectric Efficiency ◽  
Strong Anharmonicity

Band structure, phonon spectrum, and thermoelectric properties of β-BiAs and β-BiSb monolayers

2020 ◽  
Vol 8 (2) ◽  
pp. 581-590 ◽  
Author(s):  
C. Y. Wu ◽  
L. Sun ◽  
J. C. Han ◽  
H. R. Gong
Keyword(s):  
Band Structure ◽  
Thermoelectric Properties ◽  
First Principles ◽  
Phonon Spectrum ◽  
Transport Theory ◽  
First Principles Calculation ◽  
Boltzmann Transport ◽  
Band Structures ◽  
Boltzmann Transport Theory ◽  
Phonon Spectra

First-principles calculation and Boltzmann transport theory have been combined to comparatively investigate the band structures, phonon spectra, and thermoelectric properties of both β-BiSb and β-BiAs monolayers.

Structural, mechanical and thermodynamic properties study on Mg–Y alloys from first-principles calculations

2020 ◽  
Vol 34 (25) ◽  
pp. 2050220
Author(s):  
Yingying Chen ◽  
Xilong Dou ◽  
Wenjie Zhu ◽  
Gang Jiang ◽  
Aijie Mao
Keyword(s):  
Thermodynamic Properties ◽  
First Principles ◽  
Mechanical Stability ◽  
Elastic Anisotropy ◽  
Crystal Structure Analysis ◽  
First Principles Calculations ◽  
Phonon Spectra ◽  
Volume Entropy ◽  
Ductile Behavior ◽  
Searching Method

The structures with different compositions of the binary Mg–Y alloys have been predicted by first-principles calculations combined with an unbiased Crystal structure Analysis by Particle Swarm Optimization (CALYPSO) structure searching method. The two already known stoichiometries alloys of Mg1Y1 with Pm-[Formula: see text] symmetry and Mg3Y1 with Fm-[Formula: see text] are confirmed, and a new stoichiometry alloy of Mg1Y3 with [Formula: see text] symmetry is proposed. The dynamical and mechanical stabilities for the three alloys at different pressures are investigated by phonon spectra and mechanical stability criteria, respectively. Subsequently, the bulk modulus, shear modulus, Young’s modulus, the brittleness/ductile behavior, the elastic anisotropy as well as Vickers hardness for the three alloys at 0 GPa are discussed in detail. The results show that the Mg1Y1, Mg3Y1 and Mg1Y3 alloys improve the hardness and stiffness compared with pure Mg, and Mg1Y3 alloy is of the best ductility in the three alloys. Meanwhile, the three alloys exhibit anisotropic. Moreover, the thermodynamic properties, such as Debye temperature, heat capacity at constant volume, entropy and Helmholtz free energy for the three stable alloys, are predicted and discussed.

Bond Rotations at the Si(100) Surface: Anharmonicity, Chaotic Dynamics, and Signature of Tilted-Dimer Reconstruction

1992 ◽  
Vol 291 ◽  
Author(s):  
J. Gryko ◽  
R. E. Allen
Keyword(s):  
First Principles ◽  
Chaotic Dynamics ◽  
Rotation Angle ◽  
Chaotic Behavior ◽  
Bond Rotation ◽  
Atomic Displacements ◽  
Rotation Mode ◽  
The Fourier Transform ◽  
Dynamics Simulations ◽  
Strong Anharmonicity

ABSTRACTIn our first-principles-based molecular dynamics simulations for Si(100), we have found that the total energy U(θ) is rather flat with respect to the bond-rotation angle θ for |θ| <10°, with shallow minima at the positions θ = ± θ0 corresponding to a tilted-dimer geometry. Here we calculate the Fourier transform of the atomic displacements, u(ω), and find a characteristic bond-rotation mode with v − 5 THz. This mode is primarily associated with the upper atom in a dimer, and appears to be a signature of the tilted-dimer reconstruction. At low temperature the vibrations are nearly harmonic, but at high temperature there is strong anharmonicity, and θ appears to exhibit chaotic behavior.

Spin-manipulated phonon dynamics during magnetic phase transitions in triangular lattice antiferromagnet CuCr1−xMgxO2 semiconductor films

RSC Advances ◽  
2016 ◽  
Vol 6 (32) ◽  
pp. 27136-27142 ◽  
Author(s):  
Xurui Li ◽  
Junyong Wang ◽  
Jinzhong Zhang ◽  
Yawei Li ◽  
Zhigao Hu ◽  
...  
Keyword(s):  
Phase Transitions ◽  
First Principles ◽  
Magnetic Phase ◽  
Magnetic Phase Transitions ◽  
First Principles Calculations ◽  
Semiconductor Films ◽  
Temperature Dependent ◽  
Phonon Spectra ◽  
Phonon Dynamics ◽  
Triangular Lattice Antiferromagnet

The temperature-dependent phonon spectra and magnetoresistance of CuCr1−xMgxO2 films have been studied, combined with first-principles calculations.

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