Fig. 1. (a) XRD patterns and (b) DSC curves of the as-quenched Fe82.65-xCoxSi2B14Cu1.35 (x = 0-20) ribbons.

Fig. 2. The Co content dependence of (a) Bs, (b) μe and (c) Hc for Fe82.65-xCoxSi2B14Cu1.35 (x = 0-20) alloys treated by NA and FA at optimum condition, as well as the AQ state.

Fig. 3. Bs and Hc for the Fe-based amorphous and nanocrystalline soft magnetic alloys developed in the last ten years.

Fig. 4. The temperature dependence of magnetization for all the alloys.

Fig. 5. Magnetic domain patterns of Fe66.65Co16Si2B14Cu1.35 ribbon samples at (a) AQ, (b) NA and (c) FA states. (d) Hysteresis loops of Fe66.65Co16Si2B14Cu1.35 ribbon samples at AQ, NA and FA states. Partial enlarged plot is given as the inset.

Fig. 6. (a) DSC curves for Fe66.65Co16Si2B14Cu1.35 ribbons at AQ, NA and FA states. The inset demonstrates a partial enlargement. (b) Synchrotron XRD of Fe66.65Co16Si2B14Cu1.35 ribbon samples treated by NA and FA. The inset shows the enlarged image of the gray area.

Fig. 7. The HRTEM images and the corresponding FFT patterns for Fe66.65Co16Si2B14Cu1.35 ribbons at (a) AQ, (b) NA and (c) FA states. Representative auto-correlation images of typical cells with (d, f) crystal-like and (h) typical most disordered orders, and the corresponding FFT patterns (e, g, i). (j-l) Auto-correlation maps for the selected parts of the HRTEM images of (a-c). The cells showing crystal-like order and the most disordered feature are marked by red and orange rectangles, respectively.

Fig. 8. HAADF STEM images and the corresponding mappings of AQ and annealed Fe66.65Co16Si2B14Cu1.35 at 370 °C for 15 min.

Fig. 9. The bright-field TEM images, SAED patterns, grain size distribution, HAADF STEM images and corresponding EDS mappings of Cu element for samples treated by NA and FA at 375 °C for 5 min.

Fig. 10. Experimental and fitting creep curves of the Fe66.65Co16Si2B14Cu1.35 ribbons at (a) AQ, (b) NA, and (c) FA states at different loading rates. (d) The histogram of the fitting parameters of creep curves for the Fe66.65Co16Si2B14Cu1.35 ribbons at AQ, NA and FA states based on the Maxwell-Voigt model.

Fig. 11. The relaxation spectra of Fe66.65Co16Si2B14Cu1.35 ribbons at (a) AQ, (b) NA, and (c) FA states under different loading rates with a maximum load of 80 mN. (d) The relaxation spectra of Fe66.65Co16Si2B14Cu1.35 ribbons at AQ, NA and FA states under the loading rate of 10 mN/s.

Fig. 12. Schematic diagram of magnetic domain and atomic structures of Fe66.65Co16Si2B14Cu1.35 AAs in the AQ, NA and FA states. The blue balls denote the atoms forming completely disordered microstructure, and the red balls denote the atoms forming crystal-like clusters. Groups of atoms with different background colors refer to different magnetic domains, where the fluctuations of the easy magnetization direction are indicated by the arrows.