Liquid-immiscibility-induced formation of micron-scale crystalline/amorphous composite powder

Liquid immiscible alloy systems present a unique opportunity in developing the micron-scale crystalline/amorphous composite powder using the gas atomization method. On the basis of the CALPHAD approach, the compositions of Co–Si–B–Cu alloys system exhibiting the liquid immiscibility have been designed. The produced gas-atomized powders show a Cu-rich crystalline/Co–Si–B rich amorphous composite microstructure. The above-mentioned powders possess almost the same coercive force as that of Co–Si–B amorphous powders, while their saturation magnetization decreases with increasing Cu concentration. Such Cu-rich crystalline/Co–Si–B rich amorphous composite powders may have applications in the field of heat release of soft magnetic devices and ferrofluids.

► This is the original report the formation of micron-scale gas-atomized alloy powders with the crystalline/amorphous microstructure utilized by liquid immiscibility. ► We first report that micron-scale gas-atomized alloy powders were thinned by focused-ion beam (FIB) instrument before TEM observation. ► The produced powders possess almost the same coercive force as that of Co–Si–B amorphous powders, while their saturation magnetization decreases with increasing Cu concentration.