Study of NiCuZn ferrite powders and films prepared by sol gel method

This paper reports that a series of NiCuZn ferrite powders and films are prepared by using sol-gel method.The effects of raw material composition and the calcinate temperature on magnetic properties of them are investigated.The NiCuZn ferrite powders are prepared by the self-propagating high-temperature synthesis method and subsequently heated at 700 C～1000 C.The results show that NiCuZn ferrite powders with single spinel phase can be formed after heat-treating at 750 C.Powders obtained from Ni 0.4 Cu 0.2 Zn 0.4 Fe 1.9 O 4 gel have better magnetic properties than those from gels with other composition.After heat-treating at 900 C for 3 h,coercivity H c and saturation magnetization M s are 9.7 Oe (1 Oe=80 A/m) and 72.4 emu/g,respectively.Different from the powders,NiCuZn films produced on Si (100) from the Ni 0.4 Cu 0.2 Zn 0.4 Fe 2 O 4 gel formed at room temperature possess high properties.When heat-treating condition is around 600 C for 6 min,samples with low H c and high M s will be obtained.The minimal H c is 16.7 Oe and M s is about 300 emu/cm 3.In comparison with the films prepared through long-time heat treating,the films prepared through short heat-treating time exhibits better soft magnetic properties.