Room-temperature hyperpolarization of polycrystalline samples with optically polarized triplet electrons: pentacene or nitrogen-vacancy center in diamond?

Koichiro Miyanishi, Takuya F. Segawa, Kazuyuki Takeda, Izuru Ohki, Shinobu Onoda, Takeshi Ohshima, Hiroshi Abe, Hideaki Takashima, Shigeki Takeuchi, Alexander I. Shames, Kohki Morita, Yu Wang, Frederick T.K. So, Daiki Terada, Ryuji Igarashi, Akinori Kagawa, Masahiro Kitagawa, Norikazu Mizuochi, Masahiro Shirakawa, Makoto Negoro

Research output: Contribution to journalArticlepeer-review

8 Scopus citations

Abstract

We demonstrate room-temperature 13C hyperpolarization by dynamic nuclear polarization (DNP) using optically polarized triplet electron spins in two polycrystalline systems: pentacene-doped [carboxyl-13C] benzoic acid and microdiamonds containing nitrogen-vacancy (NV-) centers. For both samples, the integrated solid effect (ISE) is used to polarize the 13C spin system in magnetic fields of 350-400 mT. In the benzoic acid sample, the 13C spin polarization is enhanced by up to 0.12 % through direct electron-to-13C polarization transfer without performing dynamic 1H polarization followed by 1H-13C cross-polarization. In addition, the ISE has been successfully applied to polarize naturally abundant 13C spins in a microdiamond sample to 0.01 %. To characterize the buildup of the 13C polarization, we discuss the efficiencies of direct polarization transfer between the electron and 13C spins as well as that of 13C-13C spin diffusion, examining various parameters which are beneficial or detrimental for successful bulk dynamic 13C polarization.

Original languageEnglish
Pages (from-to)33-48
Number of pages16
JournalMagnetic Resonance
Volume2
Issue number1
DOIs
StatePublished - 1 Jan 2021

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Analytical Chemistry
  • Atomic and Molecular Physics, and Optics

Fingerprint

Dive into the research topics of 'Room-temperature hyperpolarization of polycrystalline samples with optically polarized triplet electrons: pentacene or nitrogen-vacancy center in diamond?'. Together they form a unique fingerprint.

Cite this