Metastability of fcc-related Si-N phases
2008 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 78, no 13, 132103-132103 p.Article in journal (Refereed) Published
The phenomenon of superhardening in TiN/SiNx nanocomposites and the prediction of extreme hardness in bulk gamma-Si3N4 have attracted a large interest to this material system. Attempts to explain the experimental findings by means of first-principles calculations have so far been limited to static calculations. The dynamical stability of suggested structures of the SiNx tissue phase critical for the understanding of the nanocomposites is thus unknown. Here, we present a theoretical study of the phonon-dispersion relations of B1 and B3 SiN. We show that both phases previously considered as metastable are dynamically unstable. Instead, two pseudo-B3 Si3N4 phases derived from a L1(2)- or D0(22)-type distribution of Si vacancies are dynamically stable and might explain recent experimental findings of epitaxial SiNx in TiN/SiNx multilayers.
Place, publisher, year, edition, pages
2008. Vol. 78, no 13, 132103-132103 p.
National CategoryNatural Sciences
IdentifiersURN: urn:nbn:se:liu:diva-16093DOI: 10.1103/PhysRevB.78.132103OAI: oai:DiVA.org:liu-16093DiVA: diva2:133143
Björn Alling, Eyvas Isaev, Axel Flink, Lars Hultman and Igor Abrikosov , Metastability of fcc-related Si-N phases, 2008, Physical Review B. Condensed Matter and Materials Physics, (78), 13, 132103.
Copyright: American Physical Society