Synthesis Of BaTiO₃ Nanocomposites And Their Electromagnetic Properties

With the rapid development of electronic and information technology, the popularity of wireless networks and electronic equipment is increasing, and the electromagnetic waves fill with our living space. Meanwhile, in the military field, stealth technology is an important technology to achieve information, avoid beening obtained information, and fight for the initiative of the war. Therefore, the study of absorbing materials is of great significance for the civil and military fields.In this paper, we prepared the barium titanate with perovskite structure by high temperature solid-phase method, chemical co-precipitation method and sol-gel method respectively. Compared with the other two methods, the barium titanate prepared by sol-gel method had the best structure and morphology, high purity, good dispersion. What’s more, the particle size of the sample was homogeneous. So we prepared Ba_1-xAg_xTiO₃, Ba_1-xNd_xTiO₃ and BaTiO₃/MWCNTs nanocomposites by sol-gel method to change the complex permittivity and improve the electromagnetic wave absorption performance.The effects of Ag and Nd doping amount of barium titanate structure, morphology and electromagnetic wave absorbing properties were carried out. Whether Nd or Ag doping, the complex permittivity of the nanocomposites were significantly improved. Especially under low absorbing thickness, the absorbing loss value was developed and the absorbing band was broadened. An optimal RL peak of 31 dB was obtained at 14.8 GHz and the bandwidth with the loss over 10 dB was about 2.6GHz when the doping quantity of Ag is 0.2%. At the same time, the electromagnetic wave absorption performance was the most optimal when the doping quantity of Nd was 0.2%.We prepared the BaTiO₃/MWCNTs nanocomposites and studied its absorbing properties. When the content of MWCNTs was 2.5%, the maximum value of absorbing loss was 34.4dB and the absorbing band was up to 4.1GHz, which was the optimal electromagnetic wave absorption performance. The study showed that Ba_1-xAg_xTiO₃, Ba_1-xNd_xTiO₃ and BaTiO₃/MWCNTs nanocomposites were absorbing materials with broad application prospects.