氧化物法NiCuZn铁氧体的低温烧结特性、磁导率及显微结构

Sintering Behavior, Permeability and Microstructure of Low Temperature Sintered NiCuZn Ferrites Prepared by Solid Reaction Method

用固相反应法(氧化物法)制备了成分为Ni_(1-a-x)Zn_xCuaFe_(2-δ)O_4(0.15≤a<0.25,0.1≤x≤0.65)的NiCuZn铁氧体超细粉。研究了材料的烧结特性,给出了烧结样品的起始磁导率μi、品质因数Q、表观密度d、预烧、烧结收缩率η等随烧结温度的变化。由收缩率、相对比饱和磁化强度σsp/σs的烧结温度曲线讨论了致密化过程与固相反应的关系。由烧结样品形貌分析SEM照片讨论了起始磁导率与晶粒尺寸等显微结构因素的关系,以及细晶粒和异常晶粒的生长过程。获得了在870+10℃烧结温度下μi>835+10%、Q>140、比温度系数α<1×10-6/℃、居里温度TC=130℃、电阻率ρ>1012Ω·cm、比损耗因子tgδ/μ<8.4×10-6的良好性能。其μQ=12.3×104,是Sol-Gel法的2倍。

The fine powder of Nil-a-xZnxCuaFe2-δO4（0.15≤a〈0.25,0.1≤x≤0.65） ferrites was prepared by solid reaction method. The sintering temperature dependence of initial permeability ,μi, Q value, shrinkage factor η, density d are shown and discussed. The densification and solid reaction are studied with the reduced specific saturation magnetization σsp/σss and shrinkage factor η. The influence of grain size and microstructure on the initial permeability was discussed by SEM photographs. The NiCuZn ferrites prepared by milling oxides were obtained with properties： μi 〉835±10 %, Q〉145, tan δ/μ〈8.4×10^-6, a〈1×10^-6/℃, Tc： 130℃, ρ〉10^12^12Ω· cm at sintering temperature 870±10 ℃. The μQ product of 12.3 ×10^4 is two times that of sample prepared by sol-gel method.