Phase Formation, Sintering Behavior, and Magnetic Properties of Low‐Temperature Fired Mg–Cu–Zn Ferrites
The phase formation, sintering behavior, and magnetic properties of Mg–Cu–Zn ferrites with composition Mg1−x−y
with 0.4 ≤ x ≤ 0.8; 0 ≤ y ≤ 0.35; and 0 ≤ z ≤ 0.06 were investigated. Ferrite formation from starting oxides is complete at 900°C. To guarantee sufficient densification at 900°C substoichiometric
compositions with small iron deficiency z = 0.02 are required. Substitution of Cu for Mg with 0 ≤ y ≤ 0.35 in a ferrite with x = 0.5 has minor effect on permeability only; however,
the shrinkage is significantly shifted to temperatures as low as T < 900°C. The permeability is mainly governed by the Zn concentration; μ increases from μ = 200 to 700 as x increases from x = 0.4 to 0.6, whereas
simultaneously the Curie temperature is reduced from 180°C to 40°C, respectively. Mg–Cu–Zn ferrites represent an interesting alternative to Ni–Cu–Zn
ferrites with large potential for multilayer applications.