Correlations between active species density and iron nitride layer growth in Ar-N2-H2microwave post-discharges

Abstract

Correlations are demonstrated between the production of N, H and NH active species in an Ar-N₂-H₂ microwave flowing post-discharge and the thickness of epsilon and gamma ' layers on a pure iron substrate. The Fe_2-3N, epsilon -layer thickness increases with N atom density when oxide layers are simultaneously removed by H atoms. A maximum has been found in the post-discharge reactivity when the H₂/N₂ density ratio is in the 10^-3-10^-2 range.