MOSSBAUER-EFFECT STUDIES ON AMORPHOUS AND NANOCRYSTALLINE FE73.5CU1NB3SI13.5B9

Amorphous and nanocrystalline Fe73.5Cu1Nb3Si13.5B9 were studied by conversion electron and transmission Mossbauer effect measurements. The Curie temperature T(c) of the ferromagnetic amorphous phase was determined to (602 +/- 2) K. The formation of nanocrystals from the amorphous alloy can be initiated by annealing the sample at 520-degrees-C. The kinetics of crystallization was observed by annealing the samples for 2, 4, 8, 16, 32 and 60 min and studying the state of the alloy by Mossbauer spectroscopy. The sample annealed for 60 min consisted of about 50% of the amorphous and about 50% crystalline phase. The structure of the crystalline phase is dominated by Fe-Si (DO3) with 21% Si. Other crystalline phases such as Fe-B were found. For the remaining amorphous phase a description is given. It consists of a phase with a hyperfine field distribution like the as-quenched alloy and of a new "emaciated" amorphous phase that develops during the crystallization.