Structure and magnetic properties of melt-spun Tb0.27Dy0.73Fex ribbons

The structure and magnetic properties of the melt-spun ribbons of Tb0.27Dy0.73Fex alloy are investigated as a function of various wheel speeds during melt-quenching using a single-roll technique. It is found that Tb0.27Dy0.73Fex alloy is difficult to be fabricated as amorphous state by using the melt-quenching method. X-ray diffractions show that all these ribbons for x=1.7−2.0 are the MgCu2-type phase at the wheel speed of 45 m s−1. For Tb0.27Dy0.73Fex alloy, the high wheel speed is beneficial to eliminate the RFe3 phase and form the perfect MgCu2-type phase. Compared with the bulk of Tb0.27Dy0.73Fe1.95, these ribbons exhibit higher intrinsic coercivity value and their saturation magnetizations increase as well. The magnetostriction of Tb0.27Dy0.73Fe1.95 composite with 4% epoxy resin is 640×10−6 at 900 kA m−1.