溶胶凝胶自蔓延燃烧法制备NiZnCoCu铁氧体粉体

Preparation of sol-gel auto-combustion NiZnCoCu ferrite powders

以金属硝酸盐和柠檬酸等为原料,利用溶胶凝胶自蔓延燃烧法制备了Ni0.5–xZn0.5Co0.1CuxFe1.9O4(x=0,0.10,0.15,0.20)粉体,将粉体在800℃下热处理2 h,通过FT-IR、XRD、SEM和VSM对粉体的物相结构和磁性能进行分析。结果表明,自蔓延燃烧粉体以Ni Zn Co铁氧体为主晶相,其中含有Fe2O3杂相,煅烧后杂相消失。煅烧有效推动了晶界移动,实现晶粒的长大。煅烧前后两类粉体的饱和磁化强度都随着Cu的含量增加而逐渐减小,同时矫顽力也都先减小后增加,其中煅烧粉体的磁性能较自蔓延粉体均得到提升。

Ni0.5–xZn0.5Co0.1CuxFe1.9O4（x=0, 0.10, 0.15, 0.20） ferrite powders were synthesized by sol-gel auto-combustion using citric acid as gel and metal nitrates as raw materials, then these powders were sintered for 2 h under 800℃. Magnetic properties and phase structure of the ferrite powders were analyzed and characterized by FT-IR, XRD, SEM and VSM. The results show that NiZnCo ferrites is the main crystal phase, among them including impurity phase Fe2O3 in auto-combustion powders, impurity phase may be disappeared after calcination. Calcination effectively promotes the grain boundary migration, and realizes grain’s growing up. The saturated magnetization decreases gradually with the increase of Cu substitution for the two kinds of powders before and after calcination. Meanwhile, the coercivity monotonically decreases firstly, then increases. The magnetic properties of calcined powder are improved than those of powders without calcination.