Development of high-capacitance dielectric nanocube textured ceramics by using opal-structure templates

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K15039
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 26030:Composite materials and interfaces-related
• Research Institution: University of Yamanashi
• Principal Investigator: Ueno Shintaro 山梨大学, 大学院総合研究部, 准教授 (40647062)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: ナノ結晶 / 誘電材料 / 形態制御 / ソルボサーマル法 / 複合材料 / コア-シェル構造

Outline of Final Research Achievements

The BaTiO3 (core)-KNbO3 (shell) composite nanocube particles, which are the building blocks of high-capacity composite dielectric ceramics, were prepared by epitaxial growth of KNbO3 shell layers on uniform BaTiO3 nanocubes under the optimal solvothermal conditions. These BaTiO3-KNbO3 nanocube assemblies, which were prepared on the opal-structured films by the simple precipitation, showed the partial crystallographic orientation, though the aggregation of nanocubes prevented the formation of highly-oriented assemblies. Therefore, the BaTiO3-KNbO3 composite nanocubes were assembled by the more promising technique utilizing phase-separation of liquids, and the high relative-density assemblies (>75%) could be obtained. Moreover, it was found that the dielectric constant of the BaTiO3-KNbO3 composite nanocube assembly was more than twice that of the BaTiO3 nanocube assembly.

Free Research Field

無機材料科学

Academic Significance and Societal Importance of the Research Achievements

当該研究課題は新規大容量セラミックキャパシタ材料を開発することであり、既存の高比誘電率材料がエピタキシャル界面を介して接合したBaTiO3 (core)-KNbO3 (shell)複合ナノキューブの合成法を実現し、そのエピタキシャル界面で高い誘電特性が発現することを明らかにした。また新たに確立した相分離による集積法は、これまでにない高い相対密度の集積体の作製を可能とし、常温下で緻密なセラミックスの作製に繋がる成果が得られた。もしこの低温緻密化技術が発展すれば、セラミックス産業における大規模な省エネルギー化や低炭素化に貢献できるものと考える。