Stability and elasticity of metastable solid solutions and superlattices in the MoN--TaN system: First-principles calculations

Abstract

In order to develop design rules for novel nitride-based coatings, we investigate trends in thermodynamic, structural, elastic, and electronic properties of Mo 1−x Ta x N single-phase alloys together with (MoN)1−x/(TaN)_#{x} superlattices. Our calculations predict that hexagonal Mo1−xTaxN are the overall most stable ones, followed by the disordered cubic solid solutions and superlattices. The disordered cubic systems are energetically clearly favoured over their ordered counterparts. To explain this unexpected phenomenon, we perform an in-depth structural analysis of bond-lengths and angles, revealing that the disordered phase is structurally