Sintering behaviors, magnetic and electric properties of Bi–Zn co-doped Co2Y ferrites

The Bi and Zn substitution effects on the sintering behaviors, magnetic and electric properties of hexagonal ferrites with a composition of 2(Ba1−xBixO)·2(ZnyCo0.8−yCu0.2O)·6(Fe2−x/3Znx/3O3) were investigated. The results showed that the addition of Bi and Zn can significantly promote Co2Y densification. The Y phase may be triggered to decompose into M and spinel phases at high sintering temperatures (above 1050 °C) for samples with excess Bi (x = 0.2) substitution, which resulted in densification and magnetic properties degradation. Co2Y ferrites with x = 0.1 and y = 0.4 sintered at 1050 °C show a relative density of 94%, a high initial permeability of 4.5, a quality factor (Q) of 50.

► The densification of Co2Y can be significantly promoted by the substitution of Bi and Zn. ► The substitution of excess Bi (x = 0.2) may degrade the initial permeability and relative dielectric permeability. ► The substitution of excess Bi promoted Y phase decomposition into M phase. ► The Co2Y ferrites with x = 0.1 and y = 0.4 sintered at 1050 °C show a relative density of 94%, a high initial permeability of 4.5, a quality factor (Q) of 50.