Activation energy in crystallization process of Tb-Fe and Tb-Fe-Si amorphous alloys

Thermal stability of Tb-Fe and Tb-Fe-Si amorphous alloys prepared by a de sputtering has been investigated, focusing on the activation energy of the crystallization process. The temperature of the maximum energy release T-m determined by differential scanning calorimetry (DSC) is rapidly increased by addition of Si up to 2 at.%, and the gradual increase is caused up to 20 at.%. In the crystallization process, the activation energy determined by Kissinger's peak shift method is increased about 1.8 times as high as that of the Tb-Fe binary amorphous alloy by adding of only 2 at.% Si. The addition of Si effects on the diffusion process in the phase transition from the metastable amorphous to the stable crystalline state, and hence improves the thermal stability of the Tb-Fe amorphous alloys.