Layering effects on low frequency modes in n-layered MX2 transition metal dichalcogenides

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21230%2F16%3A00238023" target="_blank" >RIV/68407700:21230/16:00238023 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1039/c5cp06788j" target="_blank" >http://dx.doi.org/10.1039/c5cp06788j</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1039/c5cp06788j" target="_blank" >10.1039/c5cp06788j</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Layering effects on low frequency modes in n-layered MX2 transition metal dichalcogenides

Popis výsledku v původním jazyce

n-Layered (n = 2, 3, 4) MX2 transition metal dichalcogenides (M = Mo, W; X = S, Se, Te) have been studied using DFT techniques. Long-range van der Waals forces have been modeled using the Grimme correction to capture interlayer interactions. We study the dynamic and electronic dependence of atomic displacement on the number of layers. We find that the displacement patterns mainly affected by a change in the layer number are low-frequency modes at Γ and A k-points; such modes are connected with the intrinsic tribological response. We disentangle electro–phonon coupling by combining orbital polarization, covalency and cophonicity analysis with phonon band calculations. We find that the frequency dependence on the number of layers and the atomic type has a non-trivial relation with the electronic charge distribution in the interlayer region. We show that the interlayer electronic density can be adjusted by appropriately tuning M–X cophonicity, acting as a knob to control vibrational frequencies, hence the intrinsic frictional response. The present results can be exploited to study the electro–phonon coupling effects in TMD-based materials beyond tribological applications.

Název v anglickém jazyce

Layering effects on low frequency modes in n-layered MX2 transition metal dichalcogenides

Popis výsledku anglicky

n-Layered (n = 2, 3, 4) MX2 transition metal dichalcogenides (M = Mo, W; X = S, Se, Te) have been studied using DFT techniques. Long-range van der Waals forces have been modeled using the Grimme correction to capture interlayer interactions. We study the dynamic and electronic dependence of atomic displacement on the number of layers. We find that the displacement patterns mainly affected by a change in the layer number are low-frequency modes at Γ and A k-points; such modes are connected with the intrinsic tribological response. We disentangle electro–phonon coupling by combining orbital polarization, covalency and cophonicity analysis with phonon band calculations. We find that the frequency dependence on the number of layers and the atomic type has a non-trivial relation with the electronic charge distribution in the interlayer region. We show that the interlayer electronic density can be adjusted by appropriately tuning M–X cophonicity, acting as a knob to control vibrational frequencies, hence the intrinsic frictional response. The present results can be exploited to study the electro–phonon coupling effects in TMD-based materials beyond tribological applications.

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

JK - Koroze a povrchové úpravy materiálu

OECD FORD obor

—

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

2016

Kód důvěrnosti údajů

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

Název periodika

Physical Chemistry Chemical Physics

ISSN

1463-9076

e-ISSN

—

Svazek periodika

18

Číslo periodika v rámci svazku

6

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

7

Strana od-do

4807-4813

Kód UT WoS článku

000369509100064

EID výsledku v databázi Scopus

2-s2.0-84957563015