J 2024

Defect-induced properties of MoSi2/Nb(Ta)Si2 disilicide nanocomposites

VŠIANSKÁ, Monika, Jana PAVLŮ and Mojmír ŠOB

Basic information

Original name

Defect-induced properties of MoSi2/Nb(Ta)Si2 disilicide nanocomposites

Authors

VŠIANSKÁ, Monika (203 Czech Republic, belonging to the institution), Jana PAVLŮ (203 Czech Republic, belonging to the institution) and Mojmír ŠOB (203 Czech Republic, guarantor, belonging to the institution)

Edition

Materials Today Communications, AMSTERDAM, Elsevier Science, 2024, 2352-4928

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

10403 Physical chemistry

Country of publisher

Netherlands

Confidentiality degree

není předmětem státního či obchodního tajemství

References:

Impact factor

Impact factor: 3.800 in 2022

Organization unit

Faculty of Science

UT WoS

001215649600001

Keywords in English

Disilicides; C11(b) MoSi2; C40 NbSi2; C40 TaSi2; Nanocomposites; Interfaces; Vacancies; Si and Al impurities; Segregation energies

Tags

Tags

International impact, Reviewed
Změněno: 23/9/2024 13:06, Mgr. Pavla Foltynová, Ph.D.

Abstract

V originále

Research on disilicide nanocomposites, as modern materials with promising technological applications, is very desirable these days. Our ab initio analysis concentrates on the C11(b) (tetragonal) MoSi2/C40 (hexagonal) NbSi2 or TaSi2 nanocomposites containing 12 types of interfaces formed by (110) planes in the C11(b) and (0001) planes in the C40 disilicide. The most stable nanocomposites are MoSi2(AC)/Nb(Ta)Si-2(BAC), MoSi2(AB)/Nb(Ta)Si-2(CAB) and MoSi2(AB)/Nb(Ta)Si-2(ABC). The interfaces reveal positive formation energies, e.g. gamma(BA)(IF) = 0.63670 J.m(-2) and gamma(CA)(IF) = 0.63727 J.m(-2) in the Nb system and gamma(BA)(IF) = 0.57837 J.m(-2) and gamma(CA)(IF) = 0.57802 J.m(-2) in the Ta system. In the most stable C(11)b-MoSi2(AC)/C40-Nb(Ta)Si-2(BAC) nanocomposite, the effect of the impurities (Al, Si), vacancies or their aggregates on the stability and structure is investigated. It turns out that (i) vacancies preferentially form at the Si positions in the third (first) layer of MoSi2 in the Nb (Ta) systems, utilising an energy of 2.259 eV.Va(-1) (1.971 eV. Va(-1)); (ii) Al impurities prefer Si positions, and it is easier to introduce them into the Ta system than into the Nb one; however, this does not apply if Al is in the Mo position; (iii) Si impurities prefer Ta positions to Nb ones, and the bulk to interfacial ones; (iv) the Si-Si divacancy is the least destabilising among divacancies; and (v) Al impurities in both systems prevent the formation of Si vacancies, and the Si impurities simplify the formation of vacancies in the Nb system. As there is very little experimental information on the structure and properties of these interfaces, most of the present results are theoretical predictions which may motivate future experimental work.

Links

LQ1601, research and development project
Name: CEITEC 2020 (Acronym: CEITEC2020)
Investor: Ministry of Education, Youth and Sports of the CR
90254, large research infrastructures
Name: e-INFRA CZ II