First-principles quantum molecular calculations of structural and mechanical properties of TiN/SiNx heterostructures, and the achievable hardness of the nc-TiN/SiNx nanocomposites

TiN/SiNx heterostructures with one monolayer of the interfacial SiNx have been investigated in the framework of first-principles molecular dynamics calculations in the temperature range of 0 to 1400K with subsequent static relaxation. The atomic configurations, thermal stability and stress–strain re...

Full description

Saved in:
Bibliographic Details
Published in:Thin solid films 2015-03, Vol.578 (C), p.83-92
Main Authors: Ivashchenko, V.I., Veprek, S., Argon, A.S., Turchi, P.E.A., Gorb, L., Hill, F., Leszczynski, J.
Format: Article
Language:English
Subjects:
Achievable hardness
First-principles molecular dynamics
Hardness
Heterostructures
Ideal strength
Mathematical analysis
Nanocomposites
Silicon nitride
Slabs
Stress–strain relations
Superhard nanocomposites
Thermal stability
TiN/SiNx heterostructures
Titanium nitride
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:TiN/SiNx heterostructures with one monolayer of the interfacial SiNx have been investigated in the framework of first-principles molecular dynamics calculations in the temperature range of 0 to 1400K with subsequent static relaxation. The atomic configurations, thermal stability and stress–strain relations have been calculated. Among the heterostructures studied, only the TiN(111)/SiN/TiN(111) and TiN(111)/Si2N3/TiN(111) ones are thermally stable. Upon tensile load, decohesion occurs between the TiN bonds adjacent to the SiNx interfacial layer for TiN(001)/SiN/TiN(001) and TiN(111)/Si2N3/TiN(111) heterostructures, and inside the TiN slab for TiN(001)/Si3N4/TiN(001) and TiN(110)/SiN/TiN(110) ones. Upon shear, failure occurs in TiN near the interfaces in all the heterostructures, except for the TiN(001)/Si3N4/TiN(001) one, for which the plastic flow occurs inside the TiN slab. Based on these results we estimate the maximum achievable hardness of nc-TiN/Si3N4 nanocomposites free of impurities to be about 170GPa. •Interface stability in TiN/SiNx heterostructures at T≤1400K is studied by quantum molecular dynamics.•Ideal decohesion and shear strengths of the heterostructures have been calculated.•Achievable hardness of nc-TiN/Si3N4-like nanocomposites of about 170GPa is calculated.•Experimentally achieved lower hardness is limited by flaws, such as oxygen impurities.
ISSN:0040-6090
1879-2731
DOI:10.1016/j.tsf.2015.02.013