2. Experiment
The Fe58.75Cr29.4Co11.85 alloy was prepared by induction melting together electrolytic Fe, Cr, Co and thermomagnetically treated to achieve hard magnetic state. Following TMT was applied: ageing at 1570 K for 1 h and ice-water quench- ing (A), cooling from 970 to 890 K at the rate 60 K/h in external magnetic field H = 300 kA/m (B), holding in 880 K for 2 h (C), cooling from 870 K to 820 K (D) and then to 770 K (E) at the rate 10 K/h, ageing at 770 K for 12 h (F) and for 150 h (G).
After each stage of TMT (A—G) the magnetic properties such as: coercivity (He), residual magnetization (Mr ) and saturation magnetization (Ms ) were mea- sured using DC hysteresigraph. Simultaneously, the phase structure was analyzed by electron microscopy (for stage F and G) and the Mössbauer transmission spec- troscopy. The Mössbauer spectra were computer analyzed using Hesse—Rubartsch's method for determination of the magnetic hyperfine field distribution (P(B)), and by the least squares fitting program assuming Lorentzian lines. All measurements were performed at room temperature.