An ab initio study of mechanical and dynamical stability of MoSi2

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68081723%3A_____%2F18%3A00493530" target="_blank" >RIV/68081723:_____/18:00493530 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216224:14310/18:00106459

Výsledek na webu

<a href="http://dx.doi.org/10.1016/j.jallcom.2018.01.241" target="_blank" >http://dx.doi.org/10.1016/j.jallcom.2018.01.241</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.jallcom.2018.01.241" target="_blank" >10.1016/j.jallcom.2018.01.241</a>

Jazyk výsledku

angličtina

Název v původním jazyce

An ab initio study of mechanical and dynamical stability of MoSi2

Popis výsledku v původním jazyce

We present a quantum-mechanical study of changes in the electronic structure, total energy, elastic properties, phonon spectra and structure of molybdenum disilicide (MoSi2) with tetragonal C11(b) structure due to uniaxial strains along the [001] direction, biaxial (epitaxial) loads within the (001) plane as well as triaxial (volumetric) strains/stresses. Total energies and optimized structural parameters are computed by the Vienna Ab initio Simulation Package (VASP) using the local density approximation (LDA). When simulating extreme loading conditions that may be relevant for highly-strained regions we predict a semi-metal to metal phase transition that is connected with the onset of mechanical instability for higher values of triaxial loads as well as many other multi-axial loading conditions. The instability is assessed by both rigorous Born-Huang's criteria connected with elastic stiffness coefficients as well as by phonon spectra computed for all three straining modes. The values of theoretical tensile strength of MoSi2 for uniaxial, biaxial and triaxial loading corresponding to the first phonon instability amount to 30, 41 and 35 GPa, respectively. We show that the semi-metal to metal transition is connected with the softening of acoustic phonons at the G point rather than with the instability of other phonon modes. (C) 2018 Elsevier B.V. All rights reserved.

Název v anglickém jazyce

An ab initio study of mechanical and dynamical stability of MoSi2

Popis výsledku anglicky

We present a quantum-mechanical study of changes in the electronic structure, total energy, elastic properties, phonon spectra and structure of molybdenum disilicide (MoSi2) with tetragonal C11(b) structure due to uniaxial strains along the [001] direction, biaxial (epitaxial) loads within the (001) plane as well as triaxial (volumetric) strains/stresses. Total energies and optimized structural parameters are computed by the Vienna Ab initio Simulation Package (VASP) using the local density approximation (LDA). When simulating extreme loading conditions that may be relevant for highly-strained regions we predict a semi-metal to metal phase transition that is connected with the onset of mechanical instability for higher values of triaxial loads as well as many other multi-axial loading conditions. The instability is assessed by both rigorous Born-Huang's criteria connected with elastic stiffness coefficients as well as by phonon spectra computed for all three straining modes. The values of theoretical tensile strength of MoSi2 for uniaxial, biaxial and triaxial loading corresponding to the first phonon instability amount to 30, 41 and 35 GPa, respectively. We show that the semi-metal to metal transition is connected with the softening of acoustic phonons at the G point rather than with the instability of other phonon modes. (C) 2018 Elsevier B.V. All rights reserved.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2018

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of Alloys and Compounds

ISSN

0925-8388

e-ISSN

—

Svazek periodika

746

Číslo periodika v rámci svazku

MAY

Stát vydavatele periodika

CH - Švýcarská konfederace

Počet stran výsledku

9

Strana od-do

720-728

Kód UT WoS článku

000429170300087

EID výsledku v databázi Scopus

2-s2.0-85042911985