气溶胶传播可怕?其实溶胶—凝胶法在材料制备

 新闻资讯     |      2020-02-14 04:38

气溶胶传播可怕?其实溶胶—凝胶法在材料制备中有大用处

最近因为新冠肺炎,气溶胶这个名词火遍了大江南北。


什么是气溶胶?


气溶胶是指悬浮在气体介质中的固态或液态颗粒所组成的气态分散系统。当含有病毒的飞沫在空气中悬浮,并逐渐失去水分,剩下的蛋白质和病原体组成核,就形成了飞沫核。


其实溶胶体系是个大家族,除了气溶胶、还有以液体为分散介质的溶胶、以固体为分散介质的固溶胶。而溶胶—凝胶法,作为一种新型制备方法,在材料研究领域得到了广泛应用。


清华大学李敬锋教授研究团队采用溶胶凝胶法制备了Sm掺杂铁酸铋(001)外延薄膜并研究了它的铁电畴和相变,发表在Journal of Materiomics第4卷第1期。查看全文可访问https://www.sciencedirect.com/science/article/pii/S2352847817300631#!


倒易空间图和透射电镜照片;不同温度下最大压电响应的变化


内容简介:


BiFeO3, a room-temperature multiferroic material, has recently been increasingly applied as a potential lead-free piezoelectric material due to its large piezoelectricity achieved by doping.


由于通过掺杂能取得较高元气棋牌的压电性能,室温多铁材料铁酸铋BiFeO3近来被越来越多作为有潜力的无铅压电材料而被应用。




In this work, 12% Sm-doped BiFeO3 epitaxial thin films were fabricated on Nb-doped SrTiO3 (001) single crystal substrates via sol-gel method.


本工作通过溶胶凝胶法在(001)单晶掺铌钛酸锶SrTiO3衬底上制备了掺杂12%Sm的BiFeO3外延薄膜。




The epitaxy was verified by reciprocal space mapping (RSM) and transmission electron microscope (TEM). The TEM results indicated the coexistence of R3c andPbam phases in the film.


通过倒易空间图和透射电镜确认了外延性。透射电镜也确认了R3c和Pbam相在该薄膜中的共存。




The 约战武汉棋牌 domains and piezoelectric properties from room temperature to 200 °C were characterized by piezoresponse force microscopy (PFM).


通过压电力显微镜测试了薄膜从室温到200℃的畴结构和压电响应的变化。




Domains became active from 110 °C to 170 °C, and domain configurations changed obviously. A partially fading piezoresponse indicated the emergence of antiferroelectric Pbam. The in-situ domain analysis suggested that the phase transition was accompanied by domain wall motion. Switching spectroscopy PFM (SS-PFM) was further conducted to investigate the piezoresponse during the phase transition.


在110℃到170℃,畴变得非常活跃,畴结构发生明显改变。部分消失的压电响应说明了Pbam反铁电相的出现。原位的畴分析说明了相转变伴随着畴壁的移动。极化翻转谱压电力显微镜进一步确认了相变时云顶棋牌的压电响应变化。




Anomalous responses were found in both ON and OFF states at 170 °C, and the film exhibits typical antiferroelectric behavior at 200 °C, implying that the completion of phase transition and structure turned to the Pbam phase.


在170℃,On和OFF状态的测试中都出现了异常的响应,说明了相变的发生。而在200℃时薄膜表现出标准的反铁电的响应,说明了相变的完成,薄膜结构完全转变到Pbam相。




This work revealed the origin of the high piezoresponse of Sm-doped BiFeO3 thin films at the morphotropic phase boundary (MPB).


本工作揭示了处于准同型相界成分的Sm掺杂BiFeO3薄膜高压电响应的起因。




棋牌游戏

文中部分图片:


在20°C, 80°C, 140°C 和200°C下,压电力显微镜扫描结果


从20 °C到200 °C,薄膜变形量和畴区域的变化


从40 °C到230 °C,光功率热分析结果


On和Off状态下,从20 °C到200 °C的变形量和相