CALORIMETRIC STUDY OF AMORPHOUS FE80.3HO1.7B18

Amorphous ribbons of Fe80.3Ho1.7B18 have been studied by differential scanning calorimetry and by magnetization measurements. The Curie temp erature, determined from both methods, is T-C=628 K and the primary cr ystallization appears up to T-m=800 K. Comparison with results where t he rare earth is replaced by Er shows that Ho leads to better thermal and magnetic stabilities than Er. The crystallization kinetics, analyz ed from the Kissinger method, provides an apparent activation energy o f 6.4 eV, a value attesting to the good stability of the amorphous sta te of this system.