Effect of chromium substitution on the gamma and neutron radiation shielding properties of calcium hexaferrite nanoparticles

For the first time, chromium substituted calcium hexaferrite (CaCr x Fe 12 - x O 19 (x = 0,2,4,6 and 8)) nanoparticles (NPs) are synthesized by Musaparadisiaca (banana) peel extract mediated solution combustion method followed by calcination at 500 o C. The Bragg reflections confirms the formation of M-type hexaferrite with P6 3 / m m c space group. No other impurity peaks are observed, except the variation in intensity and width of the peaks. The surface morphology consists irregular shaped NPs. Agglomeration of NPs was found to be maximum at CaCr x Fe 12 - x O 19 (x = 8). The optical energy band gap was calculated using Wood and Tauc’s relation which found to be in the range 3.31 to 2.92 eV. The energy band gap decreases whereas the crystallite size increases with increase in chromium substitution. The radiation shielding parameter- mass attenuation coefficient is measured and its derivatives such as mean free path, half value layer, effective atomic number, electron density, energy absorbing building factor variation at different energy region are discussed in detail along with neutron shielding and Bremsstrahlung radiation parameters with respect to chromium concentration in calcium hexaferrite NPs. These parameters plays an important role in radiation dosimetry.