Dabra Navneet, Hundal Jasbir S, Sekhar Koppole Chandra, Nautiyal Arvind, Nath Rabinder
Applied Physics and Materials Science Laboratory, Department of Applied Sciences, Baba Farid College of Engineering and Technology, Punjab, India.
IEEE Trans Ultrason Ferroelectr Freq Control. 2009 Aug;56(8):1627-33. doi: 10.1109/TUFFC.2009.1227.
The composite films of ferroelectric potassium nitrate (KNO3):poly(vinyl alcohol) (PVA) with different weight percentages of KNO3 have been prepared at 200 degrees C using the spray-deposition technique. The remanent polarization (Pr) and peak current density for all composite films was estimated by tracing the polarization-electric field (P-E) hysteresis loop and current density-electric field (J-E) loop, respectively, using a modified Sawyer-Tower circuit. Pure KNO3 is known not to exhibit any ferroelectricity under ambient conditions, but the X-ray diffraction (XRD) studies of PVA:KNO3 composite films reveal the presence of a ferroelectric phase III of KNO3 in the composite films at room temperature. The composite film containing KNO(3):PVA in equal proportions shows maximum Pr and peak intensity ratio of approximately 20.10 microC/cm2 and 2.67, respectively, at room temperature. The J-E and capacitance voltage (C-V) characteristics exhibit butterfly features that supports the presence of a ferroelectric phase in the composite films. The field emission scanning electron microscopy (FE-SEM) image of the composite film containing equal proportions of KNO3 and PVA shows the homogenous distribution of spherical grains of KNO3 of size approximately 225 nm.
采用喷雾沉积技术，在200℃下制备了具有不同硝酸钾（KNO₃）重量百分比的铁电硝酸钾（KNO₃）：聚乙烯醇（PVA）复合薄膜。使用改进的索耶 - 托马森电路，分别通过追踪极化 - 电场（P - E）滞后回线和电流密度 - 电场（J - E）回线，估算了所有复合薄膜的剩余极化强度（Pr）和峰值电流密度。已知纯KNO₃在环境条件下不表现出任何铁电性，但对PVA：KNO₃复合薄膜的X射线衍射（XRD）研究表明，在室温下复合薄膜中存在KNO₃的铁电相III。含有等比例KNO₃：PVA的复合薄膜在室温下分别显示出最大Pr和峰值强度比，约为20.10 μC/cm²和2.67。J - E和电容电压（C - V）特性呈现出蝶形特征，这支持了复合薄膜中存在铁电相。含有等比例KNO₃和PVA的复合薄膜的场发射扫描电子显微镜（FE - SEM）图像显示，尺寸约为225 nm的KNO₃球形颗粒分布均匀。
