2022
Ab initio study of phase boundaries in disilicides MoSi2, NbSi2, TaSi2 and TiSi2
VŠIANSKÁ, Monika; Iva RAMBOUSKOVÁ; Aneta BENEŠOVÁ a Jana PAVLŮZákladní údaje
Originální název
Ab initio study of phase boundaries in disilicides MoSi2, NbSi2, TaSi2 and TiSi2
Autoři
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 |
| ||
| 90140, velká výzkumná infrastruktura |
|