论文部分内容阅读
以Fe(NO3)3、Ni(NO3)2和Sr(NO3)2为主要原料,通过两步柠檬酸盐溶胶-凝胶法,制备出核-壳结构SrFe12O19-NiFe2O4磁性纳米复合粉体。采用XRD、TEM、VSM及矢量网络分析仪对合成的粉体的结构、形貌及吸波性能进行了分析研究。结果表明,复合粉体的相结构与NiFe2O4含量有关,当SrFe12O19与NiFe2O4的质量比为1∶2、烧结温度为1050℃时,复合纳米粉体的相与NiFe2O4接近,核-壳结构SrFe12O19-NiFe2O4纳米复合粉体的饱和磁化强度(Ms)(51.4emu/g)比单体SrFe12O19纳米粉体(42.6emu/g)的大;但矫顽力(Hc)(336Oe)比单体SrFe12O19纳米粉体的小,在SrFe12O19与NiFe2O4的矫顽力5395～160Oe之间。在频率为8～18GHz范围内,微波吸收逐渐增强,当频率为12GHz时,SrFe12O19-NiFe2O4纳米复合粉体的微波吸收达到最大值-9.7dB,是一种性能优良的吸波材料。
The core-shell SrFe12O19-NiFe2O4 magnetic nanocomposite powder was prepared by two-step citrate sol-gel method with Fe (NO3) 3, Ni (NO3) 2 and Sr (NO3) 2 as the main raw materials. The structure, morphology and absorbing properties of the synthesized powders were analyzed by XRD, TEM, VSM and vector network analyzer. The results show that the phase structure of the composite powders is related to the content of NiFe2O4. When the mass ratio of SrFe12O19 to NiFe2O4 is 1: 2 and the sintering temperature is 1050 ℃, the phase of the composite powders is close to that of NiFe2O4. The phase structure of SrFe12O19-NiFe2O4 The saturation magnetization (Ms) (51.4 emu / g) of the nanocomposite powder is larger than that of the monolithic SrFe12O19 nanopowder (42.6emu / g), but the coercivity (Hc) Small, between the coercivity of SrFe12O19 and NiFe2O4 5395 ~ 160Oe. In the frequency range of 8 ~ 18GHz, the absorption of microwave increases gradually. When the frequency is 12GHz, the microwave absorption of SrFe12O19-NiFe2O4 nanocomposite powder reaches the maximum value of -9.7dB, which is a kind of excellent absorbing material.