BaTiO3铁电纳米膜制备及物性和微结构表征

采用脉冲激光淀积法在硅基氧化铝纳米有序孔膜版介质上（膜版孔径平均尺寸20nm,内生长Pt纳米线作为底电极一部分）制备了BaTiO3铁电纳米膜,并对其物性（铁电和介电性能）和微结构进行了表征。结果表明厚度170nm BaTiO3铁电膜的介电常数,随着测量频率的增加（103Hz至106Hz）,从400缓慢下降到350;介电损耗在低频区域（103～105Hz）从0.029缓慢增加到0.036,而在高频率区域（〉105Hz）后,则迅速增加到0.07。这是由于BaTiO3铁电薄膜的介电驰豫极化引起的。电滞回线测量结果表明,该薄膜的剩余极化强度为17μC/cm2,矫顽场强为175kV/cm。剖面扫描透射电子显微镜（STEM）图像表明,BaTiO3纳米铁电薄膜与底电极Pt纳米线直接相连接,它们之间的界面呈现一定程度的弯曲。选区电子衍射图和高分辨电子显微像均表明BaTiO3铁电薄膜具有钙钛矿型结构。在BaTiO3纳米铁电薄膜退火晶化处理后,部分Pt纳米线的再生长导致顶端出现分枝展宽现象。为了兼顾氧化铝纳米有序孔膜版内的金属纳米线有序分布和BaTiO3纳米薄膜结晶度,合适的退火温度是制备工艺过程的关键因素。

Fabrication,physical property and microstructural characterization of ferroelectric BaTiO_3 nanofilms

By pulsed laser deposition (PLD) method ferroelectric BaTiO3 nanofilms were grown on Si substrates coated by nanoporous alumina membranes (NAMs) with an average pore size of 20 nm,and metal Pt nanowires were embedded in NAMs as a part of the bottom electrode. The dielectric and ferroelectric properties,and microstructure of the BaTiO3 nanofilms were characterized. The results showed that the dielectric constant of the BaTiO3 nanofilms with a thickness of 170 nm,decreased slowly from 400 to 350 as the measur...