Structural changes in iron after nitrogen and carbon ion implantation

Abstract

Structural changes during the implantation of massive iron by 60 keV N₂+ and C⁺ ions with integral fluences of (1–3) × 10¹⁷ cm⁻² at room temperature have been investigated. Using the transmission electron microscopy technique it has been found that hexagonal ε-nitride and ε-carbide precipitation interlayers were formed in iron while implanting N₂+ and C⁺ ions. Heating in the electron microscope column has shown the nitride stability up to 600°C. At 600°C the precipitation solution has been observed. The transformation of ε-carbide precipitation into cementite occurs in C⁺ ions irradiated iron samples at 200°C. For this reason the temperature of the massive iron surface during implantation was concluded to be lower than 200°C.