On the formation of pure and Pt-doped iron silicides using ball milling

J DESIMONI AND F H SANCHEZ

JOURNAL OF PHYSICS CONDENSED MATTER

IOP PUBLISHING LTD

Lugar: Londres; Año: 2001 vol. 13 p. 2737 - 2747

0953-8984

The sequence of phase formations for elemental powders of stoichiometricFeSi2 and Fe1−xPtxSi2 (0.03 x 0.50) mixtures prepared by mechanicalalloying at room temperature in an Ar atmosphere in a horizontal mill ispresented. Sample evolution was followed by means of M¨ossbauer spectroscopyand x-ray diffraction. After the milling, the results indicate the formationof different disordered iron silicides, depending on milling time. The kineticsof iron silicide formation was also studied; a diffusion-controlled process withdecreasing nucleation rate was found. In the case of Pt-doped samples, thesegregation of Pt silicides was observed even for the smallest concentration,and no noticeable incorporation of Pt into the β-FeSi2 lattice could be inferred.Samples were also subjected to annealing at 1123 K for 4 h to produce orderingin the structures.