Publication details

Theoretical study of MoSi2/TiSi2 disilicide nanocomposites with vacancies and impurities



Year of publication 2023
Type Article in Periodical
Magazine / Source Surfaces and Interfaces
MU Faculty or unit

Faculty of Science

Keywords Disilicides; Nanocomposites; Phase boundaries; Vacancies; Si and Al impurities; Computer simulations
Description Research on disilicide nanocomposites, as modern materials with promising technological applications, is very desirable in these days. Our ab initio analysis concentrates on the C11(b) (tetragonal) MoSi2/C54 (orthorhombic) TiSi2 nanocomposites containing 14 types of interfaces formed by planes with similar arrangements (i.e. (110) planes in the C11(b) and (100) planes in the C54 disilicide). The most stable nanocomposites are MoSi2(AC)/TiSi2(DACB) with interfaces CD and BA and MoSi2(AD)/TiSi2(CADB) with interfaces DC and BA, both with the formation energy (related to standard element reference states) equal to -0.615 eV.atom(-1) and with the lowest interface energies. In the most stable and one higher-energy interface, the effect of the impurities (Al, Si) and vacancies on the stability and structure arrangement was investigated. It turned out that: (i) Al (Si) impurities occupy Si (Ti) positions in MoSi2 (TiSi2) in the 2nd and 3rd (and 4th) layer from the interface; (ii) the interfacial Si vacancy is the most stable having the formation energy of 2.568 eV.Va(-1); (iii) the least destabilising divacancy is of the Si-Si type, and (iv) Si and Al impurities simplify the formation of vacancies. 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.
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