Nickel-Zinc Ferrite Produced By Self-propagating High-temperature Synthesis

Nickel-Zinc ferrites are important electronic ceramic materials which are used in electronic devices suited for high-frequency applications in the telecommunication field, the synthesis of the powder has always been the subject of extensive studies. Besides the traditional synthesis, there are some new methods, such as: Hydrothermal synthesis . sol-gel synthesis and citrate precursor method, but all these method have not been extensive applied because of their shortcomings.Recently, with the development and maturity of Self-propagation High-temperature Synthesis (SHS) method, people try to synthesize the ferrite powder by means of SHS. Excellent property Mn-Zn Ni-Zn Mg-Mn Ba and Sr ferrites are produced by means of SHS. Compared with conventional methods, SHS has advantage in energy and time saving, highly productive, ecologically clean .SHS method is suitable for industrial production.Zn0.6 Ni0.4 Fe2O4 soft ferrite has been prepared by SHS in his paper .The SEM and XRD has been studied for Zno.6 Ni0.4 Fe2O4 annealed in different temperature and time. The results indicate that the best annealing temperature is 1100℃ for 2h. A conclusion has been drawn that when the mol percent of iron is 60%, the productions of powders and cycle samples have the best magnetic properties.ZnY,Ni (1-Y)Fe2O4 and Cobalt substituted Ni-Zn soft ferrite powders of Zn0.4Ni(0.6-a)Coa Fe2O4 are synthesized by SHS. The SHS powders and cycle samples are annealing in 1100℃ for 2h.Their magnetic, and micro structural properties are studied using XRD, VSM and SEM techniques.The studies reveal that the value of Hc Mr and Ms of the powder of Zn yNi(1-y) Fe2O4 are maximal when the value of y is 0.4. With the increasing of the value of y, the superficial grain of the cycle samples gradually grow up, which results density increase; the values of the Bs and Br of the cycle samples are maximal when the value of y is 0.4; the values of coercive force graduallydecrease.These studies also reveal that the value of Ms of the pure Ni-Zn or Co -Zn ferrites powder is low than composite Ni-Co-Zn ferrite ; Mass loss is founded in the sintering process and mass loss decreases with the increasing of the content of CoO. The values of Bs and Br of the cycle sample are minimal when the value of a is 0.4.