Sr/Fe掺杂LaMnO_3纳米微波吸收材料的制备与表征

Preparation and characterization of LaMnO_3 nano-particles doped with Sr and Fe as microwave absorption material

用溶胶-凝胶法制备A位掺Sr,B位掺Fe的纳米级LaMnO3微波吸收材料粉体,用XRD和SEM表征该材料样品的晶体结构、颗粒形貌与尺寸,测量样品的微波吸收特性和电阻率。结果表明,于800℃煅烧的样品晶体结构为钙钛矿型;颗粒形貌为棒状,长度约100 nm,直径约20 nm;电导率在半导体的电导率范围内;当样品厚度为2 mm左右、Fe含量为0.12和0.14,Sr含量为0.2时,在2-18 GHz范围内,10 dB以上吸收带宽达6.2 GHz,最大吸收峰达34 dB;样品厚度为2.21 mm时,8 dB以上吸收带宽达8.5 GHz。

LaMnO3 nano-crystalline powders were prepared by sol-gel and doped by Sr at A site with Fe at B site as an microwave absorption material. The crystal structure , the morphology and size of doped LaMnO3 powders were characterized by XRD and SEM. The microwave absorption properties and the resistivity were measured. The results show that, the powders sintered at 800 ~C possess perovskite structure and look like stick, with length about 100 nm and diameter about 20 nm. Since the conductivity of the samples is within semiconductor, it is useful that microwave is absorbed in the material. The effective band width more than l0 dB of the sample reaches 6.2 GHz and the highest absorption peak is 34 dB when the thickness of sample is 2 mm, the frequency is in the range of 2-18 GHz, Sr content is 0.2 and Fe content is 0.12 and 0.14, respectively. The effective band width more than 8 dB achieves 8.5 GHz when the thickness of sample is 2.21 mm.