Synthesis of novel Ti-alloy hydrides with high hydrogen content

2013 Fiscal Year Final Research Report

• Project/Area Number: 24760586
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Structural/Functional materials
• Research Institution: Japan Atomic Energy Agency
• Principal Investigator: ENDO Naruki 独立行政法人日本原子力研究開発機構, 原子力科学研究部門 量子ビーム応用研究センター, 博士研究員 (40611893)
• Project Period (FY): 2012-04-01 – 2014-03-31
• Keywords: 水素貯蔵材料 / 高圧合成 / 放射光 / その場観察 / TiFe / BCC / 規則－不規則変態

Research Abstract

We investigated the hydrogenation of a CsCl-type TiFe alloy at 5 GPa and 873 K by in situ synchrotron radiation X-ray diffraction measurements. After formation of a solid solution of hydrogen in TiFe, an order-disorder phase transition in the metal lattice of TiFe occurred, which yielded a BCC TiFe hydride. The unit cell volume of the BCC hydride increased by 21.0% after the hydrogenation reaction. The volume expansion was larger than that of a gamma hydride TiFeH_x (x = 1.9) prepared by hydrogenation near ambient conditions.
In order to estimate the hydrogen content of BCC hydride, we compared its lattice volume with the lattice volume of the gamma hydride at same high pressure and high temperature conditions. As a result, the lattice volume of BCC phase was almost equal to that of the gammma hydride, therefore, the hydrogen content of BCC hydride was almost equal to the gamma hydride.

Research Products

• [Journal Article] 放射光その場観察と高温高圧技術を組み合わせたTi系合金水素化物に関する研究 (2014)
  • Author(s): 遠藤成輝、齋藤寛之、町田晃彦、片山芳則
  • Journal Title: まてりあ Volume: 53(3) Pages: 96-99
  • DOI: 10.2320/materia.53.94
  • Peer Reviewed
• [Journal Article] Formation of BCC TiFe hydride under high hydrogen pressure (2013)
  • Author(s): N. Endo, H. Saitoh, A. Machida, Y. Katayama
  • Journal Title: Int. J. Hydrogen Energy Volume: 38 Pages: 6726-6729
  • DOI: 10.1016/j.ijhydene.2013.03.120
  • Peer Reviewed
• [Journal Article] Phase diagram and equation of state of TiH_2 at high pressures and high temperatures (2013)
  • Author(s): N. Endo, H. Saitoh, A. Machida, Y. Katayama, K. Aoki
  • Journal Title: J. Alloys Compd. Volume: 546 Pages: 270-274
  • DOI: 10.1016/j.jallcom.2012.08.083
  • Peer Reviewed
• [Presentation] In situ observation of hydrogenation of a CsCl-type TiFe alloy at high pressure and high temperature (2012)
  • Author(s): N. Endo, H. Saitoh, A. Machida, Y. Katayama
  • Organizer: International Symposium on Metal-Hydrogen Systems 2012 (MH2012)
  • Place of Presentation: Kyoto, Japan
  • Year and Date: 20121000
• [Presentation] Determination of a phase diagram of TiH_2 at high pressures and high temperatures for development of novel Ti-based hydrides (2012)
  • Author(s): N. Endo, H. Saitoh, A. Machida, Y. Katayama, K. Aoki
  • Organizer: IUCr Commission on High Pressure 2012 Meeting IUCrHP2012/QuBS2012
  • Place of Presentation: Mito, Japan
  • Year and Date: 20120900
• [Remarks] EXCELLENT POSTER AWARD, MH2012 International Symposium on Metal-Hydrogen systems–Fundamentals and Applications–, 21-26 Oct., 2012, Kyoto, Japan