Determination of localized surface phonons in nanocrystalline silicon by inelastic neutron scattering spectroscopy and its application to deuterium isotope enrichment

Takahiro Matsumoto, Ikumi Nomata, Takashi Ohhara, and Yoshihiko Kanemitsu
Phys. Rev. Materials 5, 066003 – Published 28 June 2021

Abstract

The hydrogen (H) isotope deuterium (D) has attracted special interest for the manufacture of silicon (Si) semiconductors, Si microchips, and optical fibers, as well as for the synthesis of isotopically labeled compounds. However, the efficient production of D or H deuteride in a controlled manner is challenging, and rational H isotope enrichment protocols are still lacking. Here, we demonstrate a highly efficient exchange reaction from H to D on the surface of nanocrystalline Si (n-Si). Fourfold enrichment of D termination was successfully achieved by dipping n-Si into a dilute D solution. By determining the surface-localized vibrational modes for H- and D-terminated n-Si using inelastic neutron scattering spectroscopy, we found that the physical mechanism responsible for this enrichment originates from the difference in the zero-point oscillation energies and entropies of the surface-localized vibrations. Theoretically, the extent of enrichment could be greatly enhanced (∼15 times) using a gas-phase reaction. This enrichment protocol, which avoids the use of precious metal catalysts, opens the way for sustainable H-to-heavy H exchange reactions.

  • Figure
  • Figure
  • Figure
  • Figure
  • Received 27 October 2020
  • Revised 5 April 2021
  • Accepted 26 May 2021

DOI:https://doi.org/10.1103/PhysRevMaterials.5.066003

©2021 American Physical Society

Physics Subject Headings (PhySH)

Polymers & Soft Matter

Authors & Affiliations

Takahiro Matsumoto1,2,*, Ikumi Nomata2, Takashi Ohhara3, and Yoshihiko Kanemitsu4

  • 1Graduate School of Design and Architecture, Nagoya City University, Nagoya 464-0083, Japan
  • 2Graduate School of Medical Sciences, Nagoya City University, Nagoya 464-0083, Japan
  • 3Neutron Science Section, J-PARC Center, Japan Atomic Energy Agency, Ibaraki 319-1195, Japan
  • 4Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan

  • *Corresponding author: matsumoto@sda.nagoya-cu.ac.jp

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 5, Iss. 6 — June 2021

Reuse & Permissions
Access Options
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review Materials

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×