Structural analysis of neutron-irradiated (Ba0.88Ca0.12Ti0.975Sn0.025)O3 ceramic

Abstract

Co-doped barium calcium stannate titanate (Ba0.88Ca0.12Ti0.975Sn0.025O3) ceramics, 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 angles and the microstrain remained constant with increase in fluence. The average crystallite size is ∼ 38 nm with anisotropy in lattice expansion observed. Rod-like grains, porous regions and agglomerations were observed in all the specimens. There was general increase in grain size with increase in fluence and the average grain size is ∼1 μm. Chemical analysis 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 as the maximum fluence has not exceeded the order of magnitude of threshold for radiation damage.