Microstructural and Property Control of Dielectrics in the La_2O_3-TiO_2 System Using Complex Colloid Particles.

使用复杂胶体颗粒的 La_2O_3-TiO_2 体系中电介质的微观结构和性能控制。

• 批准号: 63550577
• 负责人: TAKAHASHI Junichi
• 金额: $ 1.22万
• 依托单位: Nagoya Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1988
• 资助国家: 日本
• 起止时间: 1988 至 1989
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-63550577/
• 关键词: Complex Colloid; Sintering; Lanthanum Titanium Oxide; Coprecipitation; Dielectric Properties; 複合誘電体; 共沈; 酸化ランタン; 酸化チタン; 誘電体; 微粉末調製

In the present study, the powder preparation of single phase compounds in the La_2O_3- TiO_2 system was examined, and then compositional and microstructural control in the multicomponent dielectrics was also investigated by using the synthesized powders from which highly densified bodies with different microstructures could be fabricated. The results obtained are as follows.1. The double oxide powders of La_2O_3・TiO_2(LT_2) and 2La_2O_3・9TiO_2(L_2T_9) were prepared from the corresponding precursor. The rapid mixing of homogeneously mixed aqueous solutions of La- and Ti-chlorides, with an excess amount of aq.NH_3, resulted in the simultaneous precipitation of both cations in a form of X-ray amorphous colloid. Examinations of the compaction and sintering behaviors of the prepared powders showed that the most densified bodies of each specimen could be readily obtained from loosely packed powder compact.2. Structural evolution in the X-ray amorphous precursor to LT_2 was examined using IR and Raman spectroscopy. Rapid coprecipitation from an aqueous solution containing unlike cationic species yielded a complex colloid which was definitely not a mixed dispersion of single-component colloids.3. Complex dielectrics consisting of mixed phases of LT_2 and La_2Sn_2O_7(LS_2) were fabricated by controlled sintering of synthesized powders. The LT_2-LS_2 dielectrics gave positive TCC(temperature coefficient of capacitance), while the dielectric constant changed linearly from 40 to 12 with increasing LS_2 content.4. Finally, the coprecipitation method established in the present study was modified and applied to produce a more complex, 1:1:4 ternary compound in the BaO-La_2O_3-TiO_2 system.

本文首先研究了La_2O_3- TiO_2系统单相化合物的粉末制备，然后研究了用合成的粉末制备不同显微结构的高致密体的多组分烧结体的成分和显微结构控制。研究结果如下：1.以La_2O_3·TiO_2（LT_2）和2La_2O_3·9TiO_2（L_2T_9）为前驱体制备了复合氧化物粉体。La-和Ti-氯化物的均匀混合水溶液与过量的NH_3水溶液的快速混合导致两种阳离子以X射线无定形胶体的形式同时沉淀。对所制备粉末的压制和烧结行为的研究表明，每种试样的最致密的坯体可以容易地从松散堆积的粉末压制获得.用红外光谱和拉曼光谱研究了LT_2的X射线非晶前体的结构演变。从含有不同阳离子物种的水溶液中快速共沉淀得到的复合胶体肯定不是单一组分胶体的混合分散体.采用控制烧结法制备了由LT_2和La_2Sn_2O_7（LS_2）混合相组成的复合陶瓷。LT_2-LS_2复合材料的电容温度系数为正，而介电常数随LS_2含量的增加在40 ~ 12之间呈线性变化.最后，对本研究建立的共沉淀法进行了改进，并应用于BaO-La_2 O_3-TiO_2体系中制备了更为复杂的1：1：4三元化合物。

项目成果

J.Takahashi and K.Kageyama: "Compositional and Microstructural Dependence of the Dielectric Properties of Complex Low-Loss Capacitors in the La-Sn-Ti-O System." Ceramic Transactions.

J.Takahashi 和 K.Kageyama：“La-Sn-Ti-O 系统中复杂低损耗电容器介电性能的成分和微观结构依赖性”。

J.Takahashi and T.Ohtsuka: "Vibrational Spectroscopic Study of Structural Evolution in the Coprecipitated Precursors to La_2Sn_2O_7 and La_2Ti_2O_7." Journal of the American Ceramic Society. 72. 426-31 (1989)

J.Takahashi 和 T.Ohtsuka：“La_2Sn_2O_7 和 La_2Ti_2O_7 共沉淀前体结构演化的振动光谱研究”。

J.Takahashi: "The Powder Preparation of La_2Ti_2O_7 and La_4Ti_9O_<24> Using Amorphous Complex Colloid,and the Sintering Behavior of the Synthesized Powders." Proceedings of Sintering,Tokyo. 7-12 (1988)

J.Takahashi：“使用非晶复合胶体制备La_2Ti_2O_7和La_4Ti_9O_<24>粉末，以及合成粉末的烧结行为。”

J.Takahashi: "The Powder Preparation of La_2Ti_2O_7 and La_4Ti_9O_<24> Using Amorphous Complex Colloid, and the Sintering Behavior of the Synthesized Powders." Proc. of Sintering, Tokyo p.7-12(1988).

J.Takahashi：“使用非晶复合胶体制备 La_2Ti_2O_7 和 La_4Ti_9O_<24> 粉末，以及合成粉末的烧结行为。”

J.Takahashi and T.Otsuka: "Vibrational Spectroscopic Study of Structural Evolution in the Coprecipitated Precursors to La_2Sn_2O_7 and La_2Ti_2O_7." J.Am.Ceram.Soc., 72, 426-31(1989).

J.Takahashi 和 T.Otsuka：“La_2Sn_2O_7 和 La_2Ti_2O_7 共沉淀前体结构演化的振动光谱研究”。