Mechanistic Quantification of Thermodynamic Stability and Mechanical Strength for Two-Dimensional Transition-Metal Carbides

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989100%3A27740%2F18%3A10240011" target="_blank" >RIV/61989100:27740/18:10240011 - isvavai.cz</a>

Result on the web

<a href="https://pubs.acs.org/doi/10.1021/acs.jpcc.8b00142" target="_blank" >https://pubs.acs.org/doi/10.1021/acs.jpcc.8b00142</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/acs.jpcc.8b00142" target="_blank" >10.1021/acs.jpcc.8b00142</a>

Result language

angličtina

Original language name

Mechanistic Quantification of Thermodynamic Stability and Mechanical Strength for Two-Dimensional Transition-Metal Carbides

Original language description

Recently, two-dimensional (2D) materials with superior mechanical properties, unique electronic structures, and specific functionalities have stimulated considerable interest in designing novel flexible devices and multifunctional nanocomposites. However, high-throughput experiments and calculations, which are desirable for identifying those promising candidates with excellent strengths and flexibilities, remain a great challenge due to their difficulty and complexity. In the present work, a systematic investigation has been performed on the oxygen-functionalized 2D transition-metal carbides M2CO2 (M = Sc, Ti, V, Cr, Y, Zr, Nb, Mo, Hf, Ta, and W) to identify those with excellent thermodynamic stabilities and mechanical behaviors via high-throughput first-principle calculations. Our results suggest that the position and bonding/antibonding character of metallic d-band electrons play a vital role in stabilizing M2CO2, whose formation energy is below 0.2 eV/atom, a generally considered threshold observed for freestanding 2D materials, except for Sc2CO2, Y2CO2, and Cr2CO2. The synthetic effect from the surface stacking geometry and the delocalization character of d electrons provides a mechanistic quantification for periodic variation of elastic moduli and ideal strengths for M2CO2, whereas the strain-induced premature dynamic instabilities in different modes may intrinsically limit their achievable strengths, e.g., zone-center optical phonon instability for Hf2CO2 versus elastic instability for W2CO2. Detailed electronic structure analyses reveal that strong M-C bonds endow M2CO2 with excellent in-plane mechanical strengths but the appearance of different phonon instabilities when M changes from group IVB to group VIB may be attributed to the different filling characters of specific metal-dxz orbital or metal-dz 2 orbital. These findings resolve an apparent discrepancy for the preferred adsorption sites of the functional group and shed a novel view on the electronic origin of distinct mechanical strengths and flexibilities observed for different M2CO2. (C) 2018 American Chemical Society.

Czech name

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

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

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

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

Publication year

2018

Confidentiality

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

Name of the periodical

Journal of Physical Chemistry C

ISSN

1932-7447

e-ISSN

—

Volume of the periodical

122

Issue of the periodical within the volume

8

Country of publishing house

US - UNITED STATES

Number of pages

13

Pages from-to

4710-4722

UT code for WoS article

000426802500069

EID of the result in the Scopus database

2-s2.0-85042774543