Adiabatic approximation violation on electronic structure due to quantum effect of hydrogen

• Project/Area Number: 25620009
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Physical chemistry
• Research Institution: University of Tsukuba
• Principal Investigator: SEKIBA Daiichiro 筑波大学, 数理物質系, 講師 (20396807)
• Co-Investigator(Kenkyū-buntansha): HARADA Yoshihisa 東京大学, 物性研究所, 准教授 (70333317) ; MATSUO Motoaki 東北大学, 金属材料研究所, 講師 (20509038)
• Co-Investigator(Renkei-kenkyūsha): FUKUTANI Katsuyuki 東京大学, 生産技術研究所, 教授 (10228900) ; ORIMO Shinichi 東北大学, 金属材料研究所, 教授 (40284129) ; TATEYAMA Yoshitaka 物質・材料研究機構, MANA独立研究者 (70354149) ; SODEYAMA Keitaro 物質・材料研究機構, NIMSポスドク研究員 (40386610)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Project Status: Completed (Fiscal Year 2014)
• Budget Amount: ¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000); Fiscal Year 2014: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000); Fiscal Year 2013: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
• Keywords: 水素 / 断熱近似 / 軟X線発光分光 / 軟X線ラマン散乱 / 第一原理計算 / 非断熱効果 / 電子状態 / 発光分光

Outline of Final Research Achievements

A comparative study on the electronic structure between Mg2FeH6 and Mg2FeD6 was made by means of synchrotron radiation. The resonant excitation from Fe2p to unoccupied states, which induces inelastic X-ray scatterings, was used. We observed 2.6 eV Raman shift ascribed to the electronic Raman scatterings and also the vibronic Raman scatterings with ~ 100 meV shifts. A vibronic scattering can be attributed to the Fe-H or Fe-D symmetric stretch mode due to the clear isotope effect with the factor of root mean square of 2. The second excitation also appears on the spectra. This implies the strong electron-phonon coupling in this system. A large isotope effect is also seen on the electronic Raman shift. The origin is, however, still an open question, which requires further experiments.

Research Products

• [Journal Article] Multi-Phonon Excitations in Fe 2p RIXS on Mg2FeH6 (2015)
  • Author(s): Keisuke Kurita, Daiichiro Sekiba, Isao Harayama, Kenta Chito, Yoshihisa Harada, Hisao Kiuchi, Masaharu Oshima, Shigeyuki Takagi, Motoaki Matsuo, Ryutaro Sato, Katsutoshi Aoki, and Shin-ichi Orimo
  • Journal Title: Journal of The Physical Society of Japan Volume: 84
  • NAID: 210000133491
  • Peer Reviewed
• [Journal Article] Antithrombogeniciry of Amorphous deuterated carbon film prepared by RF-plasma CVD (2013)
  • Author(s): K. Ozeki, D. Sekiba, K.K. Hrakuri, T. Masuzawa
  • Journal Title: Nano Biomedinine Volume: 5 Pages: 11-17
  • Peer Reviewed
• [Journal Article] Influence of the source gas ratio on the hydrogen and deuterium content of a-C:H and a-C:D films: Plasma-enhanced CVD with CH4/H2, CH4/D2, CD4/H2 and CD4/D2 (2013)
  • Author(s): K. Ozeki, D. Sekiba, T. Suzuki, K. Kanda, M. Niibe, K.K. Hirakuri, T. Masuzawa
  • Journal Title: Applied Surface Science Volume: 265 Pages: 750-757
  • Peer Reviewed
• [Presentation] Ultra high resolution Resonance Inelastic soft X-ray Scattering for Mg2FeH6 (2013)
  • Author(s): K. Kurita, D. Sekiba, I. Harayama, K. Chito, Y. Harada, H. Kiuchi, C. Sakai, M. Oshima, K. Sodeyama, Y. Tateyama, R. Sato, M. Matsuo, S. Orimo
  • Organizer: 8th International Conference on Inelastic X-ray Scattering
  • Place of Presentation: SLAC National Accelerator Laboratory Menlo Park, California, USA
• [Remarks] 水素・量子アトミクス研究室（関場研究室）
  • URL: http://www.tac.tsukuba.ac.jp/~sekiba/