Preparation And Magnetic Properties Of Substituted Spinel Zn/Co Ferrite

Ferrites are important magnetic functional materials which are used in many fields. The synthesis of the powder has always been the subject of extensive studies. In this paper, the spinel ferrites were synthesized by oxalate co-precipitation method. The synthesizing conditions, structure and magnetic properties were groped. The structure was characterized by XRD, TG-DSC, SEM and FT-IR.The magnetic properties were tested by VSM.The main contents of this thesis are as follows:A series of nanosize spinel ferrites of ZnFe₂O₄,CoFe₂O₄ and Zn_xCo_1-xFe₂O₄ were synthesized by oxalate co-precipitation method. The results showed the specific saturation magnetization (σ_s) of ZnFe₂O₄ has a maximum at the calcining temperature is 800℃,σ_s=32.45A·m²Â·kg^-1.The specific saturation magnetization (σ_s) of CoFe₂O₄ has a maximum at the calcining temperature is 900℃,σ_s=35.95A·m²Â·kg^-1.The specific saturation magnetization (σ_s) of Zn_xCo_1-xFe₂O₄ has a maximum at x=0.3,σ_s=63.48A·m²Â·kg^-1.The doping element on Zn_0.3Co_0.7Fe₂O₄ ferrite was synthesized by oxalate co-precipitation method. The influence of doping element on Zn_0.3Co_0.7Fe₂O₄ ferrite structures and magnetic properties was discussed. The result indicated that specific saturation magnetization of Zn_0.3Co_0.7La_xFe_2-xO₄ is decreasing when x is increasing. The specific saturation magnetization of Zn_0.3Co_0.7Y_xFe_2-xO₄ has a maximum at x=0.04,σ_s=66.89 A·m²a kg^-1.