Moessbauer spectroscopy and X-ray diffraction study of 304 L stainless steel thin films

304 L stainless steel films (SS) were elaborated using an ion-beam sputtering technique. The target material was a sheet of commercial grade 304 L SS. The starting material was first analysed by both conversion electron Moessbauer spectroscopy (CEMS) and X-ray diffraction. The nonmagnetic state and f.c.c. structure of this material were confirmed. The films were deposited on various substrates with thicknesses in the 175-800 nm range. The films are found to have both b.c.c. structure and ferromagnetic character. X-ray diffraction technique was also used in order to determine the residual stresses developed during the deposition process. The second stage of the work is devoted to the evolution of the film structure as a function of annealing treatments. So isochronal and isothermal kinetics at temperatures higher than 913 K have allowed to follow the alpha --> gamma phase transformation using X-ray diffraction and CEMS technique.The X-ray diffractograms reveal the existence of both b.c.c. and f.c.c. phases. Similar results can be deduced from Moessbauer spectra due to the single line coming from the non-magnetic phase and the sextet coming from the ferromagnetic phase. In addition the CEMS spectra reveal that the ferromagnetic component is split into two parts which indicates the existence of two iron sites. 1 fig., 4 refs.(author)