Revealing the effects of melt temperature on structure and magnetic properties in Fe–Si–B–C alloy

The effects of melt temperature in range of 1150–1400 °C on amorphous structure, magnetic properties and magnetic structures of Fe–Si–B–C amorphous ribbons were systematically investigated. The results of high-resolution transmission electron microscopy confirm that there exist a number of metastable nano-scales clusters in the quenched ribbons spinning at low melt temperature (1150 and 1300 °C). The measurement of flash differential scanning calorimetry finds that the thermal stability of the quenched ribbons notably increases with melt temperature elevating, also implying that higher melt temperature favors the higher degree of amorphization for the alloy. During the crystallization annealing process, the metastable Fe23(B, C)6 phase is preferentially precipitated at high melt temperature (1400 °C). The magnetic structure analyzed by magnetic force microscope reveals that a wide and uniform distribution of domain can be obtained in the alloy spun at high melt temperature (1400 °C), and that the domain size (width and length-breadth ratio of domain) is well correlated with coercivity and effective permeability. These current results provide important insights into the correlation between melt temperature and magnetic structure of Fe-based amorphous ribbons and are helpful to guide the production of Fe-based amorphous ribbons with homogeneous and stable amorphous structure from the technical level.