ABSTRACTA series of samples of Mg0.9Mn0.1InxFe2-xO4 for x=0, 0.3, 0.5 were prepared by conventional solid-state technique. The spinel structure of this ferrite was confirmed by X-ray diffraction technique. The samples were irradiated with 50 MeV Li3+ ions with fluence 5×1013 ions/cm2. The Mössbauer studies were performed on unirradiated as well as on irradiated samples. Mössbauer study for unirradiated samples show insignificant variation of isomer shifts at both the tetrahedral and octahedral sites. On irradiation isomer shift changes from negative to positive values. This anomalous character of isomer shift after irradiation is due to a change in the electronic configuration of Fe3+ ions. The quadrupole splitting of unirradiated samples are negligibly small, indicates the presence of cubic symmetry at both the sites. On irradiation appreciable changes are observed in quadrupole splitting due to the presence of lattice strain. On irradiation super-exchange interaction energy is weakened which decrease the hyperfine field. PACS: 61.80, 76.80, 61.72
