Microstructure and Mössbauer studies on magnetostrictive Tb0.3Dy0.7Fe1.95 − xNbx(x = 0, 0.025, 0.05 and 0.075)

Alloys of Dy0.7Tb0.3Fe1.95 − xNbx (x = 0, 0.025, 0.05 and 0.075) were prepared in vacuum employing an induction furnace and investigated for the magnetic properties and microstructural features. A significant improvement in the magnetostriction has been obtained for the alloys containing Nb as compared to that of the parent alloy (x = 0). The Curie temperature and the Fe hyperfine field of the (Tb,Dy)Fe2 phase are nearly invariant despite Nb addition to the parent alloy. The microstructural features, on the other hand, indicated that another Laves phase, NbFe2 is formed as the primary phase at the expense of the undesired (Tb,Dy)Fe3 phase. From the Mössbauer studies also the formation of NbFe2 phase has been evidenced.