Gamma radiation induced microwave absorption properties of Ultra-thin barium titanate (BaTiO3) ceramic tiles over X-Band (8.2-12.4GHz)

We report the enhancement of microwave absorption properties in BaTiO3 ceramics induced by exposing under high energy gamma radiation at 5 kGy, 10 kGy and 15 kGy, gamma-ray doses in a properly shielded Co-60 gamma-radiation chamber. The tetragonality ratio (c/a) decreases with increasing gamma dose on powder samples together with the reduction of grain size from similar to 2 mu m to similar to 0.5 mu m. Further, the irradiated BaTiO3 powder based ceramic tiles are fabricated and electromagnetic (EM) measurements suggest increase in imaginary permittivity and loss tangent values (tan delta(e)) at resonance frequency of similar to 8.8 GHz. Reflection loss (RL) plots of BT tiles showed enhancement in microwave loss at higher gamma radiation doses. As per the customized requirements, two type of extremely thin ceramic tiles are obtained viz. Resonating (RL> 40 dB at 9.6 GHz) and wide-band (RL> 8 dB over entire X-band) for their possible use for MW attenuation on different objects/platforms.