锆镍掺杂量及烧结温度对M型钡铁氧体吸波性能的影响

The influences of Zr^(4+)-Ni^(2+) doping amount and sintering temperature on microwave absorption properties of M-type barium ferrite

利用溶胶-凝胶法,在1200~1400℃烧结制备了Zr^(4+)-Ni^(2+)共掺杂钡铁氧体Ba(ZrNi)xFe_(12-2x)O_(19)(x=0.6~0.9),研究了掺杂量及烧结温度对M型钡铁氧体晶相结构、微观形貌、电磁性能和吸波性能的影响。结果表明随着锆镍掺杂量和烧结温度的增加,样品的晶体结构和化学成分不发生变化,都形成了片状的单相锆镍掺杂钡铁氧体。晶粒尺寸随掺杂量增加几乎不变化而随烧结温度提高逐渐从100~300 nm增加到1~2 mm。所有样品中均可观察到多自然共振峰,自然共振强度随掺杂量的增加整体呈下降的趋势,而介电常数随烧结温度升高会显著增加。最终,1400℃烧结的掺杂量x=0.6的样品可获得最优异的吸波性能,在匹配厚度3.25 mm下,最小反射损耗为-16.4dB,同时有效吸波频宽可达5.22 GHz(8.62~13.84 GHz)。

The Zr^(4+)-Ni^(2+)co-doped barium ferrites(Ba(ZrNi)xFe_(12-2x)O_(19),x=0.6-0.9)were prepared by sol-gel method and sintered at 1200-1400℃.The influences of doping ratio and sintering temperature on crystal structure,micro morphology,electromagnetic performance and microwave absorption property of M-type barium ferrite have been studied in detail.The results show that the crystal structure has no change with the increment of doping amount and sintering temperature.All the samples form single-phase flake Zr4+-Ni2+co-doped barium ferrite.The grain size barely changes with the increasing Zr4+-Ni2+content whereas increases from 100—300 nm to 1—2 mm by improving the sintering temperature.The natural resonance peak can be observed in all the samples,and the intensities of the peaks are seen to diminish gradually with the doping amount increasing.Meanwhile,the permittivity enhances obviously with the sintering temperature improving.Eventually,the sample with x=0.6 sintered at 1400℃achieves the best microwave absorption performance with broad bandwidth of 5.22 GHz(8.62—13.84 GHz)and reflection loss of-16.4 dB at matching thickness of 3.25 mm.