Structural, optical, morphological, electrical and positron annihilation studies of Zn-Cu nanoferrites irradiated from the D-D neutron generator

This work examines neutron-induced damage in nanocrystalline Zn1-xCuxFe2O4 to understand how the material degrades under high-radiation environments. The samples were synthesised via the sol–gel method and irradiated with a D–D neutron generator at doses of 2.4 and 7.2 Sv, with the required dose levels estimated using PHITS simulations. Neutron irradiation-induced defects, as well as structural, morphological, and electrical modifications, were examined using Doppler-broadening positron annihilation spectroscopy (DB-PAS), X-ray diffraction (XRD), photoluminescence (PL) spectroscopy, scanning electron microscopy (SEM), and dielectric measurements. XRD results revealed the formation and growth of CuO and ZnO secondary phases with increasing dose. DB-PAS measurements showed an increase in the S-parameter, indicating the generation of open-volume defects, while the linear S–W correlation suggested a stable chemical environment for positron annihilation. PL spectra (λexc = 400 nm) exhibited red–orange emissions, and SEM imaging confirmed irradiation-induced morphological changes. Dielectric measurements demonstrated a frequency-dependent decrease in the dielectric constant, with enhanced low-frequency polarisation attributed to radiation effects.