基于钛酸锶钡铁电陶瓷的温度调控型声子晶体研究

发布时间：2018-06-18 12:07

本文选题：铁电陶瓷 + 声子晶体　；参考：《湘潭大学》2015年硕士论文

【摘要】：声子晶体是由两种或者两种以上材料空间周期排列形成的人工结构,其质量密度和弹性常数呈空间周期性分布,能够对声波或者弹性波的传播进行周期调控,从而实现多种新奇物理效应:如禁带、负折射、局域模式等。这些效应为研制新型功能声学器件(如:隐身材料、隔声材料、波导、传感器、滤波器等)提供了坚实物理基础。如何进一步灵活调控声波或者弹性波传播是拓宽声子晶体应用的关键因素。在不改变声子晶体几何构成和材料组分的同时,对其特性进行调控,将会实现声子晶体的智能化应用,具有重要的研究价值。为了实现这一目标,本研究工作使用钛酸锶钡-Ba0.7Sr0.3TiO3(BST)铁电陶瓷材料制备一种声子晶体板,研究其温度可调控性能和在操控微纳米颗粒上的应用。通过BST声子晶体板实现对增强透射峰温度调控的研究:制备锶钡元素比为3:7的钛酸锶钡。经制备和测量,该BST铁电陶瓷在293 K为四方相,其纵波速度和横波速度小于313 K的立方相,由此可实现声子晶体在293 K和313 K下声学性能的调控。具体表现为通过对设计的声子晶体板仿真模拟,在293 K时,入射平面波在2.47 MHz和3.35 MHz会产生增强透射效应,而把温度升高至313K,其增强透射峰的频率为2.93 MHz和4.07 MHz,偏移量达到了19%和21%。同样,实验测量结果表明,第一和第二个增强透射峰,由293 K的2.40 MHz和3.33 MHz偏移到313 K的2.83 MHz和3.94 MHz,偏移量有18%,理论结果预实验结果匹配良好。最后从物理机制上分析了该增强透射效应的产生和偏移,该增强透射峰是由声子晶体对Lamb波的调制作用产生,其增强透射频率与纵波速度和横波速度有关,所以偏移由温度变化引起BST的相变决定。基于BST声子晶体板的声辐射力受温度调控的研究:声辐射力受声场形态影响,可以由声子晶体板所调控。通过仿真模拟分析了基于BST的声子晶体板对声辐射力的温度调控作用,在293 K下颗粒受到负向(靠近声子晶体板的吸引力)的声辐射力,而在313 K下颗粒受到正向(远离声子晶体板的排斥力)声辐射力的作用。而且293 K时负向声辐射力大小是313 K时正向声辐射力大小的3倍之多。通过场分布和能带结构分析发现,这种区别是由于在293 K时,声场分布为倏逝场,而313 K时声场分布为行波场。这些结论对拓展铁电陶瓷在声子晶体上的应用,提高温度调控声子晶体的应用价值,有着重要的意义。
[Abstract]:The phononic crystal is an artificial structure formed by space cycle of two or more than two kinds of materials. Its mass density and elastic constants are spatially periodic, and can regulate the propagation of sound waves or elastic waves periodically, so as to achieve a variety of novel physical effects, such as the forbidden band, negative refraction and local mode. Type functional acoustic devices (such as stealth materials, sound insulation materials, waveguides, sensors, filters, etc.) provide a solid physical basis. How to further flexibly regulate the propagation of sound waves or elastic waves is a key factor in broadening the application of phononic crystals. In order to realize the intelligent application of phononic crystal, it has important research value. In order to achieve this goal, a kind of phononic crystal plate is prepared by using barium strontium titanate -Ba0.7Sr0.3TiO3 (BST) ferroelectric ceramics. The temperature controllable performance and the application on the manipulation of micro nano particles are studied. The enhancement of the enhancement is achieved through the BST phonon crystal plate. Study on the regulation of transmission peak temperature: preparing barium strontium titanate with the ratio of strontium barium to 3:7. After preparation and measurement, the BST ferroelectric ceramic is tetragonal in 293 K, its longitudinal wave velocity and the shear wave velocity are less than 313 K cubic phase, thus the acoustic properties of the phononic crystals under 293 K and 313 K can be regulated. The specific performance is the sound crystal through the design of the phononic crystal. In the plate simulation, at 293 K, the incident plane waves will increase the transmission effect at 2.47 MHz and 3.35 MHz, and increase the temperature to 313K. The frequency of the enhanced transmission peak is 2.93 MHz and 4.07 MHz. The offset is equal to 19% and 21%.. The experimental results show that the first and second enhanced transmission peaks are offset by 2.40 MHz and 3.33 MHz of 293 K. To 313 K 2.83 MHz and 3.94 MHz, the offset is 18%, the theoretical results are well matched. Finally, the generation and migration of the enhanced transmission effect is analyzed from the physical mechanism. The enhanced transmission peak is produced by the modulation effect of the phononic crystal on the Lamb wave, and its enhanced radio-frequency rate is related to the longitudinal and transverse velocity and the transverse wave velocity, so the migration of the enhanced transmissive rate is related to the wave velocity. The phase transition of BST is determined by the temperature change. The sound radiation force based on the BST phonon crystal plate is controlled by the temperature control. The sound radiation force is influenced by the sound field shape. The sound radiation force can be controlled by the phonon crystal plate. The temperature regulation effect of the phononic crystal plate based on BST is simulated and analyzed. The particle is negatively (close to) under 293 K. The sound radiation force of the phononic crystal plate, while at 313 K, is affected by the sound radiation force of the positive (away from the phonon crystal plate repelling force). And the negative acoustic radiation force at 293 K is more than 3 times the size of the positive acoustic radiation force at 313 K. The difference is found by the field distribution and the band structure analysis. The difference is due to the sound at 293 K. The field distribution is evanescent field, while the sound field of 313 K is traveling wave field. These conclusions are of great significance for expanding the application of ferroelectric ceramics in phononic crystals and improving the application value of temperature regulated phonon crystals.
【学位授予单位】：湘潭大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ174.1;O735

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