Simulation of X-ray diffractograms obtained by grazing incidence X-ray diffraction of implanted stainless steel

A method to interpret grazing incidence X-ray diffractograms observed for expanded phases occurring after Mo implantation in an austenitic steel was extended to Ag and N ion implantation in austenitic or ferritic stainless steels. Theoretical X-ray diffractograms were built taking into account the information depth profile, the implanted element concentration depth profile and a linear relationship between implanted element concentration and lattice parameter through an expansion coefficient (k). Experimental X-ray diffractograms were adjusted to the theoretical ones. The adjustment led to the determination of k and/or ion-implanted concentration profile as a function of depth. For Ag implantation in AISI 316 LVM and 430 stainless steels, the concentration depth profile was predicted using SRIM-2003 computer program and confirmed by experimental measurement using RBS. The built austenite or ferrite X-ray diffraction peaks were in good accordance with the experimental ones. k was shown to be independent on the incident angle and on the fluence but dependant on the type of initial lattice. For nitrided austenitic stainless steels, the k value was determined with N-implanted AISI 316 LVM steel. The element concentration depth profiles and k value were determined for low-energy high-flux nitrogen implantation-diffusion of AISI 304 steels. The predicted profiles were confirmed by NRA measurements. Copyright (C) 2008 John Wiley & Sons, Ltd.