权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Preparation and applications for new nano-sized ceramics using heterometallic-complexes as precursors

以异金属配合物为前驱体的新型纳米陶瓷的制备及应用

基本信息

批准号：
10045045
负责人：
SADAOKA Yoshihiko
金额：
$ 3.65万
依托单位：
Ehime University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B).
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 2000
项目状态：
已结题

项目摘要

Heterometallic oxides are one of the promising material as electrodes of fuel cells and chemical sensors. We have been proposed the thermal decomposition of heteronuclear complexes as a new method for the preparation of di- or tri-metallic oxides. We found that heterometallic oxides with relatively high specific surface area were formed at low temperature when heteronuclear hexacyano-complexes were used as precursors. The organic heteronuclear LaMn(dhbaen)(OH)(NO_3)(H_2O)_4 complex was synthesized and perovskite-type hexagonal LaMnO_3 was obtained by its thermal decomposition at 700 ℃. Particle size of the samples decomposed at 600 ℃ and 700 ℃ is ca.20 nm and 50 nm, respectively. Furthermore, homogeneous La_<1-x>Sm_xFeO_3 and YBa_2Cu_3O_7 tri-metallic oxides were prepared using same method. SmFeO_3 was applied for semiconductor-type NO_2 gas sensors and determined surface structure using XPS.The number of adsorption sites for the sample prepared by this method was larger than that by solid reaction method. On the other hand, the NASICON-type Na_3Zr_<2-(x/4)>Si_<2-x>P_<1+x>O_<12> system was prepared by sol-gel method. The sinterability was improved by an increase in x value. This seems to be caused by the liquid phase sintering. This dense electrolyte system is suitable for the application as gas sensors. The Co_2 gas sensors using highly dense x=0.667(sample B)and x=1.333(sample C)samples show a stable EMF response in dry atmosphere which is very close to the theoretical value.

异金属氧化物是一种很有前途的燃料电池电极和化学传感器材料。本文提出了一种制备二、三金属氧化物的新方法--热分解法。我们发现，以六氰基杂多配合物为前驱体，在较低的温度下可以形成具有较高比表面积的金属氧化物。合成了LaMn（dhbaen）（OH）（NO_3）（H_2O）_4有机配合物，在700 ℃热分解得到钙钛矿型六方LaMnO_3。在600 ℃和700 ℃下分解的样品粒径分别约为20 nm和50 nm。用<1-x>同样的方法制备了均匀的La_ Sm_xFeO_3和YBa_2Cu_3O_7三金属氧化物。将SmFeO_3应用于磁控管型NO_2气敏元件，用XPS测定了样品的表面结构，结果表明，该法制备的样品比固相反应法制备的样品具有更多的吸附位。另一方面，采用溶胶-凝胶法制备了NASICON型Na_3Zr_（2-（x/4））Si_<2-x>P_（1+x）O_<12>2体系。烧结性通过x值的增加而改善。这似乎是由液相烧结引起的。这种致密的电解质体系适合于作为气体传感器的应用。用x=0.667（样品B）和x=1.333（样品C）的高密度样品制备的CO_2气敏元件在干燥气氛中表现出与理论值非常接近的稳定的电动势响应。