Influence of the nitrogen content on the structure and properties of MoNbTaVW high entropy alloy thin films

Highlights: • Synthesis of (MoNbTaVW)_1-xN_x films by cathodic arc and sputtering. • Phase transition from body to face centered cubic with increasing N content. • Phase formation is entirely controlled by the metal to N ratio in the film. • Structural change accompanied by increase in hardness and embrittlement. -- Abstract: The influence of nitrogen incorporation on the chemical composition, structure, mechanical, and electrical properties of refractory (MoNbTaVW)_1−xN_x high entropy alloy thin films is investigated. The films were synthesized by two different physical vapor deposition methods, cathodic arc deposition and direct current magnetron sputtering, onto silicon and polyimide substrates. Regardless of the deposition method, a change from body centered cubic to face centered cubic structure was observed with increasing nitrogen content in the film. This structural change was accompanied by an increase in hardness as measured by nanoindentation but also by a material embrittlement as determined from tensile straining tests.