Journal of Magnetism and Magnetic Materials 256 (2003) 227–236 AM . ossbauer comparative study of the local environment in metastable 304 stainless steel films depending on the preparation mode J.-P. Eymery a, *, N. Merakeb b , Ph. Goudeau a , A. Fnidiki c , B. Bouzabata b a Laboratoire de M! etallurgie Physique, UMR 6630 CNRS-Universit ! e de Poitiers, b # atiment SP2MI, T ! el ! eport 2, boulevard Marie et Pierre Curie, BP 30179, F-86962 Futuroscope Chasseneuil Cedex, France b Unit ! e de Recherche M! etallurgie et Mat ! eriaux, Universit ! e d’Annaba, BP 12, El Hadjar, 23200 Annaba, Algeria c Groupe de Physique des Mat ! eriaux, UMR 6634 CNRS-Universit ! e de Rouen, Facult ! e des Sciences et des Techniques de Rouen, place Emile Blondel, F-76821 Mont-Saint-Aignan Cedex, France Received 18 June 2002 Abstract The structure and local environment in metastable 304 stainless steel films grown by thermal evaporation was examined by X-ray diffraction and conversion electron M . ossbauer spectroscopy, and compared with previous results on ion-beam sputtered films. While in both cases the dominant structure is the strongly ferromagnetic a-phase, evaporated films exhibit B9.5vol% of the paramagnetic g-phase, and an enlarged hyperfine magnetic field distribution as well. For sputtered films, the 201CM . ossbauer spectrum can be fitted assuming a random solid solution with only one ferromagnetic Fe-site. On the contrary, for evaporated films, the ferromagnetic component of the spectrum requires a model assuming two different Fe-sites to be reproduced. It can be concluded that sputtered films are in a state further away from equilibrium than after preparation by thermal evaporation. The differences can be explained by the higher energy of the deposited atoms in the ion-beam sputtering process. r 2002 Elsevier Science B.V. All rights reserved. PACS: 61.10.i; 76.80.+y; 75.70.I Keywords: Magnetic thin films; M. ossbauer effect; X-ray diffraction; Stainless steel 1. Introduction Bulk 304 stainless steel (SS) normally appears in the face-centred cubic (FCC) structure (g-phase), which is non-magnetic at room temperature. However, metastable 304 SS films with body- centred cubic (BCC) structure (a-phase) and ferromagnetic behaviour may be obtained by using physical vapour deposition techniques. Dahlgren [1] showed that 304 SS films produced by the triode sputtering method at temperature between 274 and 648 K exhibit the BCC structure, whereas the coexistence of BCC and FCC structures was found when the deposition temperature is in the 648–773 K range. Barbee et al. [2] also proved that metastable ferritic 304 SS could be synthesised by *Corresponding author. Tel.: +33-5-49-49-67-35; fax: +33- 5-49-49-66-92. E-mail address: jpeymery@univ-poitiers.fr (J.-P. Eymery). 0304-8853/03/$-see front matter r 2002 Elsevier Science B.V. All rights reserved. PII:S0304-8853(02)00487-0