Ferroelectric switching in Langmuir-Blodgett and spin-coated thin films of poly(vinylidene fluoride/trifluoroethylene) copolymers
Ferroelectric switching in Langmuir-Blodgett and spin-coated thin films of poly(vinylidene fluoride/trifluoroethylene) copolymers
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DOI：
10.1063/1.3636397
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发表时间：
2011-09
影响因子：
3.2
通讯作者：
Manfang Mai;B. Martin;H. Kliem
中科院分区：
文献类型：
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作者：
Manfang Mai;B. Martin;H. Kliem
用极化开关方法研究了聚偏氟乙烯/三氟乙烯共聚物薄膜的铁电行为。在37-139 nm范围内通过Langmuir-Blodgett（LB）沉积制备的样品和在53-327 nm范围内通过旋涂制备的样品表现出几乎相同的开关行为。减小样品厚度，磁滞回线倾向于倾斜，并且开关瞬态变得更宽。矫顽场随样品厚度的减小而增大，而反射极化几乎与膜厚无关。开关时间随着电场的增加而减小，并且它几乎与LB膜的厚度无关，在LB膜中为69 nm，在旋膜中为71 nm。在LB膜和旋膜中，对于低于60 nm的厚度观察到较慢的切换。这可能是由于铝电极表面氧化层引起的退极化场，样品越薄退极化场越明显。此外，保…
Ferroelectric behaviour of poly(vinylidene fluoride/trifluoroethylene) copolymer thin films has been investigated through polarization switching measurements. Samples prepared by Langmuir-Blodgett (LB) deposition in the range of 37-139 nm and samples prepared by spin coating in the range of 53-327 nm exhibit almost the same switching behaviour. Reducing the sample thickness, the hysteresis loops tend to slant and the switching transients become broader. The coercive field increases with decreasing sample thickness, whereas the remanent polarization is nearly independent of film thickness. The switching time decreases with increasing field and it is almost independent of thickness down to 69 nm in LB films and 71 nm in spun films. Slower switching is observed for a thickness below 60 nm in both LB films and spun films. This could be due to the depolarization field induced by the surface oxidation layers of Al electrodes which becomes the more pronounced the thinner the sample is. Furthermore, retention pro...