Fundamentals of Electron Paramagnetic Resonance in Modern Carbon-based Materials

The advantages of using multifrequency Electron Paramagnetic Resonance (EPR) in studying carbon-based materials are discussed. The details of designing continuous-wave EPR spectrometers operating at different frequencies are presented. Designs of CW and pulse Electron Nuclear Double Resonance (ENDOR) spectrometers, which are very important techniques for studying precisely hyperfine interactions and local environment of paramagnetic ions in carbon-based materials are included. Analysis of EPR spectra, spin Hamiltonians, EPR lineshapes, evaluation of spin-Hamiltonian parameters, and simulation of single-crystal and powder spectra are also explained. A short review of carbon-based materials studied by EPR is given.

Keywords: Carbon-based materials, Continuous Wave EPR, Davies ENDOR, Electron spin echo (ESE), Electron Spin Echo Envelope Modulation (ESEEM), Evaluation of spin Hamiltonian parameters, Electron Nuclear Double Resonance (ENDOR), EPR, EPR lineshape, EPR spectrometer, High-frequency spectrometers, Hyperfine interaction, Hyperfine Sublevel Correlation Spectroscopy (HYSCORE), Mims ENDOR, Pulse EPR, Pulse ENDOR, Simulation of EPR spectrum, Spin Hamiltonian, Zeeman effect.