The effect of Mn and Al dopants on the β-FeSi2 stabilization by a two-step route: Mechanical alloying and annealing

J. DESIMONI; S. M. COTES; J. MARTÍNEZ; J. RUNCO; M. A. TAYLOR

JOURNAL OF ALLOYS AND COMPOUNDS

ELSEVIER SCIENCE SA

Lugar: Amsterdam; Año: 2009 vol. 477 p. 789 - 794

0925-8388

Al and Mn dopant influence on β-FeSi2 phase formation was studied using X-ray diffraction and Mössbauer spectroscopy. Samples of Fe1−xRxSi2 (R=Al, Mn with 0.00≤x≤0.12) were prepared by the simultaneous mill of pure Si, Fe and R, under Ar atmosphere followed by an annealing at 1123K during 4h at 1.33×10−5Pa. The results indicate that the addition of Al improved the stabilization of β-FeSi2 phase, reducing the amount of ɛ-FeSi from 20% to 6%. Also a preferential substitution at the Fe- site II by Mn atoms in β-FeSi2 can be inferred from the present study. The sequence of phase formation is summarised by two reactions that account for the milling and the annealing effects.