基于电卡效应反铁电厚膜致冷行为的基础研究

发布时间：2018-05-07 02:02

  本文选题：电卡效应 + 反铁电厚膜　； 参考：《内蒙古科技大学》2015年硕士论文

【摘要】：随着现代工业的飞速发展，微电子器件逐渐向集成化、小型化、轻量化和多功能化的趋势发展，导致器件温度急剧上升，严重影响器件的性能和工作寿命。因此，散热技术已经成为制约微电子器件继续微型化发展的障碍。传统的压缩致冷不能满足微电子系统局部致冷的要求，且会污染环境。基于以上事实，探索利用电卡效应的致冷技术及其器件化具有重要的意义。PbZrO3是一种典型的反铁电体，在外场的作用下，发生反铁电-铁电及反铁电-顺电相变，相变过程中会引起巨大的熵变，从而产生巨大的电卡效应。本文中采用sol-gel技术制备PbZrO3基反铁电厚膜材料，并对其电卡效应致冷行为进行深入研究。 首先，采用PVP改性的sol-gel技术制备(Pb0.97La0.02)(Zr0.75Sn0.18Ti0.07)O3反铁电厚膜，并对其显微结构、介电性能、致冷行为和漏电流性能进行深入研究。900kV/cm电场下，厚膜在5℃时获得最大的电卡效应温度变化为53.8℃，熵变为63.9J·K-1·kg-1。 其次，研究组分掺杂和组分梯度结构对反铁电厚膜显微结构、介电性能、致冷行为和漏电流性能的影响。研究表明：(Pb1-3x/2Lax)(Zr0.85Ti0.15)O3厚膜的饱和极化强度、介电常数、居里温度和漏电流密度随着La含量的增加逐渐降低，当La=8mol%时，厚膜在990kV/cm电场下获得最大的电卡效应， T=25.0℃；当Ti含量恒定，随着Zr/Sn摩尔比的增加，(Pb0.97La0.02)(Zr1-xSnxTi0.05)O3厚膜的饱和极化强度，居里温度和漏电流密度增大，当Zr/Sn摩尔比为75/20时，即位于准同型相界附近的厚膜在室温900kV/cm电场下获得最大电卡效应，， T=33.0℃；与单组分厚膜相比，(Pb1-3x/2Lax)(Zr0.85Ti0.15)O3组分梯度结构厚膜具有更优的介电性能和致冷行为，且上梯度厚膜在室温900kV/cm电场时具有最大电卡效应为T=28.2℃。 最后，研究了不同种类氧化物缓冲层和生长取向对(Pb0.97La0.02)(Zr1-xSnxTi0.05)O3反铁电厚膜显微结构及性能的影响。结果表明：引入氧化物缓冲层后，该体系厚膜的极化强度、介电常数和电卡效应均有不同程度的提高，其中，引入ZrO2缓冲层的(Pb0.97La0.02)(Zr0.57Sn0.38Ti0.05)O3反铁电厚膜在室温900kV/cm电场下获得最大的电卡效应， T=37.1℃；(Pb0.97La0.02)(Zr0.73Sn0.22Ti0.05)O3反铁电厚膜的介电性能和致冷行为具有明显的各向异性，(111)取向的厚膜在室温900kV/cm电场下具有最大的电卡效应， T=28.1℃。
[Abstract]:With the rapid development of modern industry, microelectronic devices are gradually becoming integrated, miniaturized, lightweight and multifunctional, which leads to a sharp rise in device temperature, which seriously affects the performance and working life of the devices. Therefore, heat dissipation technology has become an obstacle to the development of microelectronic devices. The traditional compression cooling can not meet the requirement of local cooling in microelectronic system, and it will pollute the environment. Based on the above facts, it is of great significance to explore the refrigeration technology and its devication using the electric card effect. PbZrO3 is a typical antiferroelectrics, and the antiferroelectric-ferroelectric and antiferroelectric phase transitions occur under the action of the external field. In the process of phase transition, a huge entropy change will be caused, which will result in a huge electric-card effect. In this paper, the antiferroelectric thick film based on PbZrO3 was prepared by sol-gel technique, and the cooling behavior of the film was studied. Firstly, the antiferroelectric thick films of Pb0.97La0.02CnZr0.75Sn0.18Ti0.07O _ 3 were prepared by PVP modified sol-gel technique. The microstructure, dielectric properties, cooling behavior and leakage current properties of the films were studied in the .900kV / cm electric field. At 5 鈩

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