COMPARISON OF THE CRYSTALLIZATION PROCESSES IN SOME SOFT AND HARD MAGNETIC MATERIALS

B. Bhanu Prasad, N. Rajya Lakshmi, M.D.V. Sri Lalitha

Abstract: The crystallization process and phase transformations in amorphous Fe68.8Si18.6B9.5Nb2.6Cu0.5, Fe78Gd2B20, Fe78Dy2B20 and Fe78Tm2B20 alloys have been studied by Differential Scanning Calorimetry (DSC), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and X-Ray Diffration (XRD). DSC of amorphous Fe68.8Si18.6B9.5Nb2.6Cu0.5 alloy showed two peaks one at 5690C and another at 7090C respectively indicating two step crystallization. XRD of the crystallized samples showed the presence of the crystalline phase a-Fe. The DSC curve of Amorphous Fe78Gd2B20 alloy showed an exothermal peak at 828 K showing the crystallization of the sample. From the DSC study, the crystallization temperature of Fe78Gd2B20 alloy was found to be 828 K. The lattice parameter ‘a’ was found to be 2.8656 Ao . From the DSC study the crystallization temperature of Fe78Dy2B20 alloy was found to be 828 K. DSC study on amorphous Fe78Tm2B20 alloy showed a sharp peak at 818 K indicating a phase transformation from amorphous to crystalline in the sample.

Keywords: crystallization, Fe68.8Si18.6B9.5Nb2.6Cu0.5, Fe78Gd2B20, Fe78Dy2B20 and Fe78Tm2B20

DOI: https://doi.org/10.15623/ijret.2015.0419004