Materials design and development of cation conductive crystal-oriented ceramics

2015 Fiscal Year Final Research Report

• Project/Area Number: 24360273
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Inorganic materials/Physical properties
• Research Institution: Nagoya Institute of Technology
• Principal Investigator: FUKUDA KOICHIRO 名古屋工業大学, 工学(系)研究科(研究院), 教授 (90189944)
• Co-Investigator(Kenkyū-buntansha): ASAKA Toru 名古屋工業大学, 工学研究科, 准教授 (80525973)
• Co-Investigator(Renkei-kenkyūsha): YOSHIDA Hideto 東京大学, 理学研究科, 技術職員 (30376553)
• Project Period (FY): 2012-04-01 – 2016-03-31
• Keywords: セラミックス / 構造・機能材料 / 環境材料

Outline of Final Research Achievements

The b-axis-oriented polycrystalline Na0.85Ti0.51Ga4.37O8 (NTGO) was prepared using the reactive diffusion technique. When the sandwich-type Ga2TiO5/NaGaO2/Ga2TiO5 diffusion couple was heated at 1323 K for 24 h, the NTGO polycrystal was readily formed in the presence of a liquid phase. We mechanically extracted the thin-plate electrolyte consisting of the grain-aligned NTGO polycrystal. The ionic conductivity of the electrolyte along the common b-axis direction steadily increased from 1.3×10-4 to 7.3×10-3 S/cm as the temperature increased from 573 to 1073 K. The NTGO showed the crystal structure (space group C2/m) with substantial positional disordering of one of the two Ga sites. The Na ions occupied ca. 43% of the Wyckoff position 4i site, the deficiency of which would contribute to the relatively high ionic conductivity along the b-axis. The reactive diffusion would be widely applicable as the novel technique to the preparation of grain-aligned ceramics of multi-component systems.

Free Research Field

工学