Structural and microstructural analyses of neutron-irradiated Ba0.88Ca0.12Ti0.975Sn0.025O3 ceramic.

Abstract

Co-doped barium calcium stannate titanate (Ba0.88 Ca0.12 Ti0.975 Sn0.025 O3) ceramics was synthesized via solid state reaction and sintered at 1100 °C/3 h. The ceramics were irradiated with thermal neutrons of up to 1.4 × 1010 n/cm2 using a 5 Ci Am-Be source having an average flux of 2.7 × 104 n/cm2.s. Structural analysis of the ceramics indicate a majorly polycrystalline material with a minor secondary phase. The 2θ positions were observed to shift slightly to higher values but the microstrain remained constant with increase in fluence. The average crystallite size is ∼ 38 nm with anisotropy observed in lattice expansion. Rod-like grains, porous regions and agglomerations were observed in all the specimens together with a general increase in grain size with increase in fluence. The average grain size is ∼ 1 μm. Chemical analysis using EDS indicates slight deviation from nominal ones for some irradiated samples. It is concluded that the structural and microstructural changes observed would not affect the performance of the devices based on this material when used in radiation environments of neutrons since the maximum fluence has not exceeded the order of magnitude of threshold for radiation damage.