Giant electrocaloric effect of free-standing Pb0.85La0.1(Zr0.65Ti0.35)O-3 thick films fabricated by the self-lift-off screen printing method
Giant electrocaloric effect of free-standing Pb0.85La0.1(Zr0.65Ti0.35)O-3 thick films fabricated by the self-lift-off screen printing method
复制标题
自剥离丝网印刷法制备自支撑Pb0.85La0.1(Zr0.65Ti0.35)O-3厚膜的巨电热效应
DOI：
10.1016/j.ceramint.2017.09.158
复制
发表时间：
2018
影响因子：
5.2
通讯作者：
Wang Qing
中科院分区：
文献类型：
--
作者：
Shen Meng;Jiang Shenglin;Li Mingyu;Liu Yang;Liu Huan;Liu Pin;Fan Baoyan;Qiu Shiyong;Zhang Guangzu;Wang Qing
采用一种简单、低成本的电热冷却自分离丝网印刷法制备了Pb 0.85La 0.1（Zr 0.65Ti 0.35）O3（PLZT）陶瓷厚膜，系统研究了制备工艺、相组成、显微结构、介电性能、铁电性能和电热效应之间的关系。与传统的由衬底支撑的陶瓷厚膜相比，自支撑特征使得自支撑PLZT厚膜的EC冷却能够充分用于冷却不同的热负荷，而不是被衬底徒劳地吸收。此外，没有衬底的机械限制，独立的PLZT厚膜可以在高温致密化过程中自由收缩，导致其高密度和良好的微观结构。此外，通过引入足够量的过量PbO，可以从样品中除去烧绿石相，以产生高纯度的钙钛矿PLZT。随着相组成、微观结构的全面改善以及活性材料与衬底之间机械应变的消除，自支撑PLZT厚膜表现出最佳的ECE，包括1.95 °C和2.09 J kg−1K−1的温度变化和熵变化，这几乎是沉积在没有过量PbO的Al2O3衬底上的样品的3倍。这一工作将有助于发展铁电陶瓷，特别是厚膜，用于实际的EC冷却。
Free-standing Pb0.85La0.1(Zr0.65Ti0.35)O3(PLZT) ceramic thick films have been prepared via a facile and low-cost self-separating screen printing method for electrocaloric cooling, and the relation among the fabrication processes, phase composition, microstructure, dielectric characteristics, ferroelectric properties and electrocaloric effect (ECE) has been systematically investigated. Compared to the conventional ceramic thick films supported by substrates, the free-standing feature enables the EC cooling of the free-standing PLZT thick films to be fully used for cooling down different thermal loads rather than be futilely absorbed by the substrates. Furthermore, without the mechanical restriction of the substrates, the free-standing PLZT thick films can freely shrink during the high-temperature densification process, leading to their high density and favorable microstructures. Additionally, by introducing an adequate amount of excess PbO, the pyrochlore phase can be removed from the samples to yield high-purity perovskite PLZTs. With the comprehensive improvement in phase composition, microstructure and the elimination of mechanical strain between the active materials and substrates, the free-standing PLZT thick films exhibited an optimized ECE including changes of temperature and entropy of 1.95 °C and 2.09 J kg−1K−1, which are almost 3 times that of the samples deposited on the Al2O3substrates without excess PbO. This work would contribute to the development of ferroelectric ceramics, especially thick films, for practical EC cooling.