title: 230/115 GHz Electron Paramagnetic Resonance/Double Electron-Electron Resonance Spectroscopy.
abstract: Electron paramagnetic resonance (EPR) and double electron-electron resonance (DEER) spectroscopies are powerful and versatile tools for studying local structures and dynamic properties of biological molecules. Similar to nuclear magnetic resonance (NMR) spectroscopy, EPR/DEER spectroscopies become more advantageous at higher frequencies and higher magnetic fields because of better spectral resolution as well as higher spin polarization. Here, we describe development of a high-frequency (HF) EPR/DEER spectrometer operating in the frequency range of 107-120 and 215-240 GHz and in the magnetic field range of 0-12.1 T, which has unique experimental capabilities such as enabling the complete spin polarization and wide-band DEER spectroscopy. Emphasis is given on the application of HF EPR/DEER techniques, and specific examples of HF EPR spectroscopy to drastically increase spin coherence in nanodiamonds as well as HF DEER spectroscopy to extract spin concentration in a diamond crystal are presented.
authors.affiliation: Department of Physics, University of Southern California, Los Angeles, California, USA.
authors.forename: Franklin H
authors.initials: FH
authors.lastname: Cho
authors.affiliation: Department of Chemistry, University of Southern California, Los Angeles, California, USA.
authors.forename: Viktor
authors.initials: V
authors.lastname: Stepanov
authors.affiliation: Department of Chemistry, University of Southern California, Los Angeles, California, USA.
authors.forename: Chathuranga
authors.initials: C
authors.lastname: Abeywardana
authors.affiliation: Department of Physics, University of Southern California, Los Angeles, California, USA; Department of Chemistry, University of Southern California, Los Angeles, California, USA. Electronic address: susumu.takahashi@usc.edu.
authors.forename: Susumu
authors.initials: S
authors.lastname: Takahashi
mesh_terms: D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D004583:Electrons; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D013113:Spin Labels; D013696:Temperature
chemical_list: D013113:Spin Labels
keywords: Diamond; Double electron–electron resonance; Electron paramagnetic resonance; High frequency; High magnetic field; Spin coherence