title: Nonequivalent spectra of unpaired electrons in field and frequency modulation.
abstract: We report a difference in the spectral lineshapes of continuous-wave (CW) electron paramagnetic resonance (EPR) spectroscopy between field and frequency modulation. This finding addresses the long-standing question of the effect of modulation in EPR absorption. We compared the first-derivative EPR spectra at 1.1 GHz for lithium phthalocyanine crystals, which have a single narrow linewidth in the EPR absorption spectrum, using field and frequency modulation. The experimental findings suggest that unpaired electrons have different behaviors under perturbation due to field and frequency modulation.
authors.affiliation: Department of Electrical Engineering, Yamagata University, Yonezawa, Yamagata 992-8510, Japan. hhirata@yz.yamagata-u.ac.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hirata
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Kuyama
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Ono
authors.forename: Yuhei
authors.initials: Y
authors.lastname: Shimoyama
mesh_terms: D004578:Electron Spin Resonance Spectroscopy / Q000295:instrumentation / Q000379:methods*; D004583:Electrons; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007211:Indoles / Q000032:analysis* / Q000737:chemistry*; D008872:Microwaves; D009942:Organometallic Compounds / Q000032:analysis* / Q000737:chemistry*
chemical_list: D007211:Indoles; D009942:Organometallic Compounds; C081756:lithium phthalocyanine