Microstructure and magnetic properties of amorphous Fe₅₁Co₁₂Si₁₆B₈Mo₅P₈ alloy

Microstructure and thermomagnetic characteristics of the amorphous Fe₅₁Co₁₂Si₁₆B₈Mo₅P₈ alloy in the as-quenched state and after 1 h of annealing at 573 K and 773 K are studied. The structural investigations performed by Mössbauer spectroscopy and X-ray diffractometry confirmed the amorphous structure of the analysed materials. An increase in the annealing temperature up to 773 K does not lead to crystallization of the amorphous alloy. Only structural rearrangement that causes changes in the topological short-range order and annealing out of free volume is observed. This behaviour was confirmed by modifications of the shapes of hyperfine field distributions derived from the corresponding Mössbauer spectra of the investigated alloys. The Curie temperatures of the as-quenched and annealed Fe₅₁Co₁₂Si₁₆B₈Mo₅P₈ alloy at 573 and 773 K are 400, 405 and 421 K, respectively.