Gamma-ray irradiation effects on electrical properties of bismuth layer-structured ferroelectric ceramics

In this study, we prepared the bismuth layer-structured ferroelectric (BLSF)-type Bi₄Ti₃O₁₂ (BiT), Bi_3.25La_0.75Ti₃O₁₂ (BLaT), and Bi_3.1Nd_0.9Ti₃O₁₂ (BNdT) ceramics using the solid-state reaction method. The prepared ceramics were irradiated at room temperature by using a ⁶⁰Co gamma-ray source in a dose range of 0–3000 kGy with a dose rate of 10 kGy/h to compare the structure and electrical properties of the irradiated ceramics. The X-ray diffraction analysis shows that the BLSF structure was well formed in all ceramics without a secondary phase. There was no structural change such as grain size change and secondary phase formation despite the cumulative gamma-ray dose of 3000 kGy. A comparison of the electrical properties with gamma-ray irradiation shows that the BiT ceramics exhibits a larger reduction ratio compared to the BLaT and BNdT ceramics. The rate of change of the remnant polarization (2P_r) value with the gamma-ray irradiation doses was − 14.2%, − 8%, and − 3.4% in BiT, BLaT, and BNdT ceramics, respectively, at a cumulative gamma-ray dose of up to 3000 kGy. Furthermore, the dielectric relaxation phenomenon in BiT ceramics at low frequency was observed when gamma rays of 1000 kGy or more were irradiated. Based on these results, in this study, we investigated the structure and electrical properties of BLSF ceramics with gamma-ray irradiation.