a 2022

Ab initio study of phase boundaries in disilicides MoSi2, NbSi2, TaSi2 and TiSi2

VŠIANSKÁ, Monika; Iva RAMBOUSKOVÁ; Aneta BENEŠOVÁ a Jana PAVLŮ

Základní údaje

Originální název

Ab initio study of phase boundaries in disilicides MoSi2, NbSi2, TaSi2 and TiSi2

Autoři

VŠIANSKÁ, Monika; Iva RAMBOUSKOVÁ; Aneta BENEŠOVÁ a Jana PAVLŮ ORCID

Vydání

Tenth International Conference on Materials Structure & Micromechanics of Fracture (MSMF10), 2022

Další údaje

Jazyk

angličtina

Typ výsledku

Konferenční abstrakt

Obor

10403 Physical chemistry

Stát vydavatele

Česká republika

Utajení

není předmětem státního či obchodního tajemství

Označené pro přenos do RIV

Ano

Kód RIV

RIV/00216224:14310/22:00128848

Organizační jednotka

Přírodovědecká fakulta

ISBN

978-80-214-6089-8

Klíčová slova anglicky

ab initio; phase boundaries; disilicides; MoSi2; NbSi2; TaSi2; TiSi2
Změněno: 10. 3. 2023 09:51, doc. Mgr. Jana Pavlů, Ph.D.

Anotace

V originále

An ab initio analysis of MoSi2-XSi2 (X = Nb, Ta, Ti) disilicide nanocomposites was performed, where the most stable configurations of non-diffusive phase boundaries were determined as follows: MoSi2(AC)/TiSi2(DACB), MoSi2(AD)/TiSi2(CADB), MoSi2(AC)/Nb(Ta)Si2(BAC), MoSi2(AB)/ Nb(Ta)Si2(CAB) and MoSi2(AB)/Nb(Ta)Si2(ABC), where A, B, C and D denote the configurations of most densely occupied crystal planes. In the case of MoSi2(AC)/TiSi2(DACB), MoSi2(AC)/TiSi2(BDAC) and MoSi2(AC)/Nb(Ta)Si2(BAC) interfaces, the influence of defects on structure properties was studied. It was found that all structures containing the defects are stable with respect to the standard element reference states despite their destabilisation effect. This was not always true when pure disilicides were used as reference states. Furthermore, the most preferred positions of vacancies, divacancies, Al and Si impurities and vacancy-impurity couples were determined together with their formation energies. However, it was necessary to be careful during the studies of vacancies as some of them may undergo recombination with interstitial impurities, as it happened in the systems with Si impurities. The destabilisation effect of vacancies can be reduced by the presence of impurities, which leads to the conclusion that the impurities can facilitate the formation of vacancies. The diffusion (exchange of Mo-X atoms across the phase boundary) caused the stabilisation of studied structures by creating a diffusive interface in some cases. The ab initio calculations were performed using the VASP code (Vienna Ab initio Simulation Package), employing the Density Functional Theory with Projector Augmented Wave method. The exchange-correlation energy was evaluated within the Local Density Approximation with the Ceperley-Alder functional.

Návaznosti

LM2018140, projekt VaV
Název: e-Infrastruktura CZ (Akronym: e-INFRA CZ)
Investor: Ministerstvo školství, mládeže a tělovýchovy ČR, e-Infrastruktura CZ
90140, velká výzkumná infrastruktura
Název: e-INFRA CZ