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Abstract. This paper describes a new method, namely modified Pechini for one, for the preparation of nano-sized ferroelectric Pb(Zr 0.53 Ti 0.47 )O 3 (PZT (53/47)) from low cost precursors. With this method, PZT (53/47) was prepared by microwave-assisted dissolving a pre-calcinated mixture of component oxides in dilute HNO 3 for a short time and precipitating in NH 4 OH solution (pH = 9-10). On the other hand, the ferroelectric thin films PZT (53/47) on Al substrates were also prepared. The films and the ceramic powders of PZT (53/47) were obtained with high quality in terms of structure and microstructure. The ferroelectric properties of thin films have also been investigated. Keywords:Ferroelectric materials, PZT (53/47), microwave-assisted, Pechini method. IntroductionThe ferroelectric Pb(Zr x Ti 1-x )O 3 (PZT), La-doped PZT (PLZT), and PbTiO 3 materials are attractive research subject not only in sense of basic research but also of applications such as in fabricating sensors and actuators. There are two common preparation methods for these compounds: a traditional solid state reaction and a sol-gel method. By using a solid state reaction, the title compounds are prepared from low cost starting materials but the prepared powders possess microscale average grain size. In contrast, the sol-gel method provides nanoscale average grain size but requires expensive precursors such as TiCl 4 or Ti[O(CH 2 )CH 3 ] 4 [1]. The advantages (nano-sized grains and low cost precussors) of these two method can be combined by applying the modified Pechini method [2]. With this method, from precursors (nitrate salts, ethylene glycol and citric acid), a fixed network enclosing the metal ions is formed and, as a result, the particles size is inhibited to grow. In addition, this method has the capability to prepare multicomponent compounds with high homogeneity.For the preparation of ferroelectric PZT and PLZT materials by wet chemical route using TiO 2 as one of starting materials, the most difficult problem is the low solubility of TiO 2 in dilute HNO 3 . J. A. Eiras et al. proposed to make the PZT solutions from pre-calcinated PZT powders. However, due to the use of normal heating calcination methods it could not be dissolved totally PZT in dilute HNO 3 [3][4][5]. In this paper, we prepare and investigate the PZT (53/47) by dissolving calcined PZT (53/47) in dilute HNO 3 using microwave-assisted power. In addition, the Pechini method was also used to prepare the ferroelectric thin films.

Background: Lotus, Nelumbo nucifera Gaertn is Vietnam’s symbol and Buddhism’s flower and plays an essential part in rural Vietnam’s economy as all aspects of lotus could bring benefits to farmers. But, unfortunately, lotus yield in Vietnam is seriously affected by various plant diseases. Among them, leaf blight is currently emerging as one of the primary diseases devastating lotus crops in Vietnam, in which there are large necrotic parts on lotus leaves, flowers and seeds. Methods: Aloe barbadensis extract was used for synthesizing silver nanoparticles. Leaf blight lotus leaves were collected to isolate pathogenic fungi-infection of isolated pathogenic fungi on the healthy lotus and then identify hidden mold by 28S rRNA sequencing. Determination of in vitro minimal inhibition concentration of nano-silver was conducted according to Azizi. The reduction of disease symptoms and biological characteristics of the treated lotus was observed. Result: Morphological analysis and molecular identification of 28S rRNA sequencing showed that the pathogenic microorganism was Mycoleptodiscus indicus (M. indicus). Both in vitro antifungal activity and in vivo treatment of leaf blight lotus using a nano-silver solution showed that 30 ppm of nano-silver was the minimal inhibition concentration (MIC) for totally eradicating M. indicus growth. This was the first time M. indicus was reported to infect and cause leaf blight on a lotus. Previously, M. indicus was a well-known plant pathogen that could cross-kingdom infect humans and animals. Thus, the fact that lotus is widely cultured in Vietnamese rural could increase the chance for M. indicus to spread; hence, this raised the alarm about its potential harm to plants, humans and animals. And, significantly, it revealed nano-silver as a possible approach to prevent M. indicus.