Preparation of Nanopartide-dispersed Hybrid-Polymer Nonlinear Optoelectronic Materials and Phase Control

纳米颗粒分散杂化聚合物非线性光电材料的制备及相位控制

基本信息

批准号：
15360341
负责人：
WADA Satoshi
金额：
$ 8.77万
依托单位：
TOKYO INSTITUTE OF TECHNOLOGY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2004
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15360341/
关键词：
Barium titanate Nanoparticle Size effect Hybrid-Polymer Materials 3D colloidal crystal Far infrared Reflection Phonon analysis Soft mode 無機-有機ハイブリッドインクプロピレンカーボネイト精密構造解析

项目摘要

A new preparation method was proposed to prepare impurity-free, defect-free barium titanate (BaTiO_3) nanoparticles using barium titanyl oxalate. This method was called a 2-step thermal decomposition method, and composed of the following two steps ; i.e., (1)1^<st> step : a preparation of intermediate compound of Ba_2Ti_2O_5CO_3 by thermal decomposition of barium titanyl oxalate in air and (2) 2^<nd> step : a preparation of BaTiO_3 nanoparticles via thermal decomposition of Ba_2Ti_2O_5CO_3 in vacuum. As the results of characterization using many kinds of measurements such as density, impurity, TG-DTA, FT-IR, Raman, TEM observation, Raman and so on, it was cleared that these BaTiO_3 nanoparticles were defect-free, impurity-free, and dense. However, there was no way to measure dielectric constant of particles. Thus, a new measurement method for powder dielectric constants was newly developed. The powder dielectric measurement of BaTiO_3 fine particles with sizes from 17 to 1,000 nm revea … More led the maximum dielectric constant at a certain particle size. Moreover, the sizes with maximum dielectric constants were strongly dependent on the preparation methods. When the BaTiO_3 fine particles were prepared using the original 2-step thermal decomposition method, a dielectric constant maximum of 15,000 was observed at 70 nm particle size. On the other hand, when the BaTiO_3 fine particles were prepared using the modified 3-step thermal decomposition method, a dielectric constant maximum of 5,000 was observed at 140 nm. To confirm the validity of these high dielectric constants, particle/polymer composite using these particles was prepared and these dielectric properties were measured. As the result, the particle/polymer composite using the high dielectric constant showed always much higher dielectric constants than those prepared using the normal dielectric constant of 3,000. The former BaTiO_3 was prepared in vacuum of 10^<-2> torr while the latter BaTiO_3 was prepared in air. Structure refinement of BaTiO_3 particles using a Rietveld method revealed that all of BaTiO_3 particles were always composed of two parts ; (a)surface cubic layer and (b)bulk tetragonal layer. Moreover, a thickness of surface cubic layer for BaTiO_3 nanoparticles prepared in vacuum of 10^<-2> torr was much thinner than that for BaTiO_3 nanoparticles prepared in air. Thus, to explain these differences, a new model on the basis of "surface relaxation" was proposed. Moreover, to measure phonon state of these particles, 3D colloidal crystals with a smooth surface were prepared, and their far infrared reflection spectra were measured. To date, there was no way to measure phonon state of nanoparticles except for Raman scattering, but using the 3D colloidal crystals, the clear far infrared reflection spectra were obtained. By the analysis of these spectra, soft mode frequency was determined for various BaTiO_3 nanoparticles. As the result, it was cleared that the dielectric constant of BaTiO_3 particles increased with decreasing soft mode frequency. Moreover, the decrease of soft mode frequency was strongly related to the thickness of surface cubic layer. Less

提出了一种新的制备方法，以制备使用钛盐酸钡的无杂质，无缺陷的钛酸钡（BATIO_3）纳米颗粒。该方法称为2步热分解方法，由以下两个步骤组成。即，（1）1^<ST>步骤：BA_2TI_2O_5CO_3的中间化合物的制备，通过空气中的黄钛硫酸铵的热分解和（2）2^<nd>步骤：BATIO_3纳米颗粒通过BA_2TITI的热分解来制备BATIO_3纳米颗粒的准备。由于使用多种测量值（例如密度，杂质，TG-DTA，FT-IR，Raman，Tem观察，拉曼等）进行表征的结果，因此可以清楚地看出，这些Batio_3纳米颗粒是无缺陷，无杂质和浓密的。但是，没有办法测量颗粒的饮食常数。这是一种新开发的粉末饮食常数的新测量方法。 Batio_3的粉末饮食测量，尺寸为17至1,000 nm的粉粒……更多的是在一定的粒径下导致最大饮食常数。此外，具有最大饮食常数的尺寸在很大程度上取决于制备方法。当使用原始的2步热分解方法制备BATIO_3细颗粒时，在70 nm粒径下观察到饮食常数最大为15,000。另一方面，当使用改进的3步热分解方法制备BATIO_3细颗粒时，在140 nm处观察到线性常数最大为5,000。为了确认这些高线性常数的有效性，制备了使用这些颗粒的粒子/聚合物复合材料，并测量了这些线性特性。结果，使用高线性常数的粒子/聚合物复合材料显示出比使用3,000的正常饮食常数制备的颗粒/聚合物复合材料始终更高。以前的batio_3是在10^<-2> Torr的真空中制备的，而后者的Batio_3是在空中准备的。使用Rietveld方法对BATIO_3颗粒的结构细化表明，所有Batio_3颗粒始终由两个部分组成。（a）表面立方层和（b）散装四方层。此外，用10^<-2> Torr制备的BATIO_3纳米颗粒的表面立方层的厚度比在空气中制备的Batio_3纳米颗粒的厚度要薄得多。为了解释这些差异，提出了一个基于“表面弛豫”的新模型。此外，为了测量这些颗粒的声子状态，制备了具有光滑表面的3D胶体晶体，并测量了其远程感染的反射光谱。迄今为止，除了拉曼散射外，还无法测量纳米颗粒的声子状态，但是使用3D胶体晶体，获得了清晰的远距离感染的反射光谱。通过对这些光谱的分析，确定了各种BATIO_3纳米颗粒的软模式频率。结果，可以清楚地看出，Batio_3颗粒的字典常数随着软模式频率的降低而增加。此外，软模式频率的下降与表面立方层的厚度密切相关。较少的

项目成果

期刊论文数量（60）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

THz Region Dielectric Properties of Barium Titanate Fine Particles using Infrared Reflection Method

红外反射法测定钛酸钡细颗粒的太赫兹区介电性能

DOI：
发表时间：
2005
期刊：
Journal of the European Ceramic Society (In press)
影响因子：
0
作者：
S.Anisul Haque;Masahiko Yamamoto;Ryoichi Nakatani;Yasushi Endo;Y.Q.Li;Satoshi Wada
通讯作者：
Satoshi Wada

Development of New Preparation Method for nm-sized Barium Titanate Particles

纳米级钛酸钡颗粒制备新方法的开发