Characterizing neutron irradiation-induced effects in the nanocrystalline B4C particles using EPR spectroscopy

The paramagnetic centers and their nature in nanocrystalline B4C particles have been comparatively studied before and after neutron irradiation. Electron Paramagnetic Resonance (EPR) spectroscopic analyses were conducted in the magnetic field range of 0.05–0.55 T (500–5500 Gauss). Furthermore, the region of 0.3270–0.3370 T, where more paramagnetic centers were observed, was specifically examined. The nature of newly formed paramagnetic centers due to the influence of neutron irradiation in B4C nanocrystalline particles has been elucidated through EPR spectra. The mechanism of VB and VC vacancy formation has been thoroughly investigated through neutron transmutation. [Display omitted] •Robust signals with g factor values consistent with free electrons were observed in the EPR spectra of nanocrystalline B4C.•The signal from a boron center is strengthened due to the increased concentration of the 11B isotope after neutron absorption.•Nuclear transmutations occurring in different directions lead to the formation of vacancies or defects under neutrons.