掺杂钛酸钡复合吸波材料的制备与性能研究

发布时间：2018-04-28 00:38

  本文选题：钛酸钡 + 碳纳米管　； 参考：《中北大学》2015年硕士论文

【摘要】：钛酸钡具有较高的介电常数及优异的铁电特性，但是单一的钛酸钡无法满足吸波材料“薄、轻、宽、强”的要求，所以本课题对钛酸钡进行了包括掺杂、复合、化学镀等方法在内的一系列改性，以期改善钛酸钡在低频区(0-6000MHz)的微波吸收性能。具体研究方法和内容如下： (1)采用溶胶凝胶法对钛酸钡进行了锰钕元素的掺杂，并对其进行了X射线衍射(XRD)、能谱分析仪(EDS)及扫描电子显微镜(SEM)的表征。吸波性能测试结果分析表明当钛酸钡中锰钕的掺杂比均为5%时，样品的吸收强度最大，达到-17.90dB。当锰的掺杂量为5%，钕的掺杂比为7%时，样品小于-5dB的有效频带宽度最大，达到1191MHz。 (2)将钕掺杂后的钛酸钡凝胶前驱体与锶铁氧体的凝胶前驱体按不同质量比混合后高温煅烧，制得了BaTiO3/SrFe12O19复合样品，，并对其进行了XRD、EDS及SEM的表征。磁性能分析结果表明当钛酸钡含量为10%时，BaTiO3/SrFe12O19复合粉末的饱和磁化强度最大，为79.96emu·g-1。当钛酸钡含量为50%时，复合样品对电磁波的吸收能力达到最强，在频率为5312.4MHz处出现了-12.70dB的最大吸收峰。 (3)采用水热法将不同质量分数的碳纳米管与钕掺杂后钛酸钡进行复合，并对复合后的样品进行了XRD、EDS及透射电子显微镜(TEM)的表征。对复合材料吸波性能的分析结果表明当CNTs复合量为7%时，复合材料具有最佳吸波特性，在频率为4270.8MHz处出现了-13.50dB的最强吸收峰，小于-5dB的频宽达到520.8MHz。 (4)采用银氨溶液作为敏化活化剂，对BaTiO3/CNTs复合材料进行金属镍钴的化学镀，考察了温度及pH值对化学镀工艺及样品吸波性能的影响。吸波性能分析表明当化学镀温度为60℃、pH值为8时，样品在5610.0MHz处具有-32.9dB最大的吸收峰，当化学镀温度为60℃、pH值为9时，小于-5dB的有效频宽达到最大，为1082MHz。最后，分析了无钯化学镀的反应机理。
[Abstract]:Barium titanate has high dielectric constant and excellent ferroelectric properties, but a single barium titanate can not meet the requirements of "thin, light, wide and strong" absorbing materials. In order to improve the microwave absorption of barium titanate in the low frequency region (0-6 000 MHz), a series of modifications including electroless plating have been carried out in order to improve the microwave absorption of barium titanate. The specific research methods and contents are as follows: (1) the doping of manganese and neodymium elements in barium titanate was studied by sol-gel method and characterized by X-ray diffraction (XRD), energy spectrum analyzer (EDS) and scanning electron microscope (SEM). The results of microwave absorption test show that when the doping ratio of mn and ND in barium titanate is 5, the absorption strength of the sample reaches -17.90 dB. When the doping amount of manganese is 5 and the doping ratio of neodymium is 7, the effective bandwidth of the sample less than -5dB reaches 1191MHz. (2) the neodymium doped barium titanate gel precursor and strontium ferrite gel precursor were calcined at high temperature according to different mass ratios, and the BaTiO3/SrFe12O19 composite samples were characterized by SEM and EDS. The results of magnetic properties analysis show that the saturation magnetization of BaTiO3 / SrFe12O19 composite powder is the highest when the barium titanate content is 10, which is 79.96emu g-1. When the content of barium titanate is 50, the absorption ability of the composite sample is the strongest, and the maximum absorption peak of -12.70 dB appears at the frequency of 5312.4MHz. (3) the carbon nanotubes with different mass fractions were prepared by hydrothermal method and the neodymium doped barium titanate was prepared. The composite samples were characterized by XRDX EDS and TEM (TEM). The results of the analysis of the absorbing properties of the composites show that the composites have the best absorbing characteristics when the CNTs recombination ratio is 70.The strongest absorption peak of -13.50 dB appears at the frequency of 4270.8MHz, and the band width less than -5dB reaches 520.8 MHz. Silver ammonia solution was used as sensitizer for electroless plating of nickel and cobalt on BaTiO3/CNTs composites. The effects of temperature and pH value on the electroless plating process and the absorbing properties of the samples were investigated. The absorbing property analysis shows that when the electroless plating temperature is 60 鈩

本文编号：1813028