Special quasirandom structure method in application for advanced properties of alloys: A study on Ti0.5Al0.5N and TiN/Ti0.5Al0.5N multilayer
2015 (English)In: Computational materials science, ISSN 0927-0256, Vol. 103, 194-199 p.Article in journal (Refereed) Published
The special quasirandom structure (SQS) approach is a successful technique for modelling of alloys, however it breaks inherently the point symmetry of the underlying crystal lattice. We demonstrate that monocrystalline and polycrystalline elastic moduli can scatter significantly depending on the chosen SQS model and even on the supercell orientation in space. Also, we demonstrate that local disturbances, such as vacancies or interfaces change the SQS configuration in a way, that significantly affects the values of the calculated physical properties. Moreover, the diversity of local environments in random alloys results in a large variation of the calculated local properties. We underline that improperly chosen, generated or handled SQS may result in erroneous theoretical findings. The challenges of the SQS method are discussed using bulk Ti0.5Al0.5N alloy and TiN/Ti0.5Al0.5N multilayer as model systems. We present methodological corrections for the mindful application of this approach in studies of advanced properties of alloys.
Place, publisher, year, edition, pages
Elsevier , 2015. Vol. 103, 194-199 p.
Modelling alloys; Special quasirandom structure approach; Elastic constants; Vacancy formation energy; Multilayers
IdentifiersURN: urn:nbn:se:liu:diva-118022DOI: 10.1016/j.commatsci.2015.03.030ISI: 000353377100024OAI: oai:DiVA.org:liu-118022DiVA: diva2:813141
Funding Agencies|SSF project Designed Multicomponent coatings, MultiFilms; Erasmus Mundus Programme of the European Commission within the Doctoral Programme DocMASE; Grant of Ministry of Education and Science of the Russian Federation [14.Y26.31.0005]; Tomsk State University Academic D.I. Mendeleev Fund Program; Swedish Research Council (VR)2015-05-212015-05-202015-05-28