The development of the phase composition in melt-spun alloys with thermal treatment: a combined NMR and Mössbauer study

The types of atomic short-range orders (SROs) in the amorphous alloy and its crystallization products under different thermal-treatment conditions were investigated by means of spin-echo nuclear magnetic resonance (NMR) and Mössbauer spectroscopy. It was found that there exist two kinds of SROs in the amorphous alloy: body-centred tetragonal (BCT) B- and orthorhombic (o) B-like SROs. The crystallization products differ at various annealing temperatures: the sample annealed at C for 10 min consists of BCT B containing Gd and -Fe, without the phase; the sample annealed at C for 60 min contains BCT B, and -Fe; and the sample crystallized at C for 10 min consists of B, -Fe, and . The experimental results indicate that the NMR peak shifts from 34.7 MHz for pure BCT B in the sample annealed at C for 60 min to 36.0 MHz for the sample annealed at C for 10 min and the relative intensity of the third Mössbauer sub-spectrum, corresponding to the (8g) site of BCT B, is about 6% less than those of the other two. These facts can be explained in terms of the entering of Gd atoms into the BCT B phase.