Implantation induced phase formation in stainless steel

After Eu implantation, the phase formation in a surface region of 150 nm of stainless steel was studied non-destructively by a depth resolved Moessbauer technique (DCEMS). The observed iron phases are characterized by the hyperfine interaction of the 57Fe nuclei. Their characteristics and depth distributions strongly depend on fluence and ion energy. A newly formed martensitic phase accompanies the implantation profile of the Eu atoms into a depth of up to about 120 nm. In a near-surface region of 15 nm, the observed phases differ from those found in larger depths. This reveals the substantial role of the surface, where implantation induced diffusion and segregation processes are effective. Concerning the DCEMS analysis, special emphasis is laid on the determination of systematic and statistical errors of the phase depth profiles