Effect of Preparation Conditions in the Pressure Range of Atmospheric Nitrogen (2 ... 50) ∙10-4 Torr on the Structural and Phase State of the Vacuum-arc Coatings of Mo-N

This work deals with the impact of the reactive atmosphere (N2) pressure and bias potential values on the phase-structural state of the coatings being formed. It has been found that at a low bias potential Ub=(0 … -40) V, and with pressure increase from 2·10-4 up to 5·10-3 Torr, phase formation takes place in the following sequence: supersaturated solid solution of nitrogen in the bcc lattice of Mo (Mo(N)) → γ-Мо2N → γ-MoN phases with the NaCl-type lattice and with different degrees of octahedral interstitial site occupation with nitrogen. At Ub=(-40 … -100) V, the sequence of phase-structural states is as follows: Мо (Мо(N)) → γ-Мо2N → e-MoN (hexagonal lattice) → δ-МоN. At highest Ub (with a strong radiation factor effect) values ranging between -150 V and -200 V and with pressure increase, the composition changes to Мо (Мо(N)) → γ-Мо2N → β-Мо2N → e-MoN → δ-МоN.