Magnetostriction of Fe-Sn polycrystalline alloys

In the present work we study the magnetostriction of Fe91Sn9 and Fe80Sn20 polycrystalline samples produced by arc melting and heat treated at temperatures of 1153 K for 6 h and 1023 K for 24 h, looking for high values of magnetostriction as in Fe-Ga alloys. Magnetostriction, as well as saturation magnetization measurements, was carried out at temperatures close to 203 K in the magnetic field interval 0 to 1.5 T. Results of magnetostriction on sample Fe91Sn9, which has almost pure alpha-phase, show magnitude and behavior similar to pure Fe. The two additional Fe80Sn20 samples have a combination of alpha-phase plus either Fe5Sn3 or Fe3Sn2 and show a peculiar behavior of the magnetostriction for mu H-0 < 0.3 T the magnetostriction grows from zero to saturation of the alpha-phase. Following, for mu H-0 > 0.3 T, the magnetostriction starts again to grow linearly with the field, but saturation was not observed up to 5 T. This behavior was attributed to the presence of Fe5Sn3 or Fe3Sn2 phases in these samples that are also ferromagnetic as the alpha-phase is. (c) 2008 Elsevier B.V. All rights reserved.