本文選題：鈦酸鋇 + 碳納米管��； 參考：《中北大學(xué)》2015年碩士論文

【摘要】：鈦酸鋇具有較高的介電常數(shù)及優(yōu)異的鐵電特性，但是單一的鈦酸鋇無法滿足吸波材料“薄、輕、寬、強(qiáng)”的要求，所以本課題對鈦酸鋇進(jìn)行了包括摻雜、復(fù)合、化學(xué)鍍等方法在內(nèi)的一系列改性，以期改善鈦酸鋇在低頻區(qū)(0-6000MHz)的微波吸收性能。具體研究方法和內(nèi)容如下： (1)采用溶膠凝膠法對鈦酸鋇進(jìn)行了錳釹元素的摻雜，并對其進(jìn)行了X射線衍射(XRD)、能譜分析儀(EDS)及掃描電子顯微鏡(SEM)的表征。吸波性能測試結(jié)果分析表明當(dāng)鈦酸鋇中錳釹的摻雜比均為5%時，樣品的吸收強(qiáng)度最大，達(dá)到-17.90dB。當(dāng)錳的摻雜量為5%，釹的摻雜比為7%時，樣品小于-5dB的有效頻帶寬度最大，達(dá)到1191MHz。 (2)將釹摻雜后的鈦酸鋇凝膠前驅(qū)體與鍶鐵氧體的凝膠前驅(qū)體按不同質(zhì)量比混合后高溫煅燒，制得了BaTiO3/SrFe12O19復(fù)合樣品，，并對其進(jìn)行了XRD、EDS及SEM的表征。磁性能分析結(jié)果表明當(dāng)鈦酸鋇含量為10%時，BaTiO3/SrFe12O19復(fù)合粉末的飽和磁化強(qiáng)度最大，為79.96emu·g-1。當(dāng)鈦酸鋇含量為50%時，復(fù)合樣品對電磁波的吸收能力達(dá)到最強(qiáng)，在頻率為5312.4MHz處出現(xiàn)了-12.70dB的最大吸收峰。 (3)采用水熱法將不同質(zhì)量分?jǐn)?shù)的碳納米管與釹摻雜后鈦酸鋇進(jìn)行復(fù)合，并對復(fù)合后的樣品進(jìn)行了XRD、EDS及透射電子顯微鏡(TEM)的表征。對復(fù)合材料吸波性能的分析結(jié)果表明當(dāng)CNTs復(fù)合量為7%時，復(fù)合材料具有最佳吸波特性，在頻率為4270.8MHz處出現(xiàn)了-13.50dB的最強(qiáng)吸收峰，小于-5dB的頻寬達(dá)到520.8MHz。 (4)采用銀氨溶液作為敏化活化劑，對BaTiO3/CNTs復(fù)合材料進(jìn)行金屬鎳鈷的化學(xué)鍍，考察了溫度及pH值對化學(xué)鍍工藝及樣品吸波性能的影響。吸波性能分析表明當(dāng)化學(xué)鍍溫度為60℃、pH值為8時，樣品在5610.0MHz處具有-32.9dB最大的吸收峰，當(dāng)化學(xué)鍍溫度為60℃、pH值為9時，小于-5dB的有效頻寬達(dá)到最大，為1082MHz。最后，分析了無鈀化學(xué)鍍的反應(yīng)機(jī)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

本文編號：1813028