Atomic displacements and structural distortions are major consequences of heavy A 205804 irradiation. These changes may leads to significant effect on metal–oxygen vibrations and their bond length, hence FTIR spectra of materials were recorded and shown in Fig. 4. As mentioned earlier, bands observed below 700 cm−1 are related with metal ion vibration for spinel structure . Other bands in the structures are related with absorbed moisture from environment, presence of carbon and nitrogen atoms in materials .