Structure, phase evolution, and mechanical properties of DC, pulsed DC, and high power impulse magnetron sputtered Ta-N films

Based on our results we can conclude that coatings dominated by Ta-rich o-Ta4N or γ-Ta2N phases exhibit the most favourable mechanical properties, according to which the most important pN2-range is between 0.04 and 0.15 Pa, as for higher N2 partial pressures the films undergo a transformation from γ-Ta2N (plus o-Ta4N) into mixed δ- and ε-TaN.