Effect of Zr on the thermal stability and magnetic properties of Fe78Si9B13 glassy alloy

The (Fe0.78Si0.09B0.13)100−xZrx (x = 0, 1 and 2) glassy alloys have been investigated in this paper. The experimental results show that the minor addition of Zr can improve the thermal stability of the Fe-based alloy. The thermal contraction process of the ribbons is mainly dependent on the crystallization process. With increasing Zr content (cZr), the difference (Δd) between the nearest neighbor distance (dexp) deduced from the X-ray diffraction pattern and the estimated nearest neighbor distance dcal, the onset crystalline temperature (Tx), the reduced crystalline temperature (Trx), the apparent activation energy (Ep1) for the first crystallization, and the difference (Δα) between the expansion coefficients of amorphous ribbons (αamor) and fully crystallized counterparts (αcryst) of the Fe-based glassy alloys first increase and then decrease, which is opposite to the change of the saturation magnetization (Ms). The variation of these parameters can be explained by the deviation degree from the equilibrium state of the amorphous ribbons. Besides the M–T measurement, the Curie temperature (Tc) of the Fe-based glassy alloys can also be scaled by the bump and inflection temperatures (Tc,dsc and Tk) in differential scanning calorimetric and dilatometric curves, respectively, showing a slight decreasing tendency with increasing cZr.