Insight into the effects of gamma radiation on MLCCs: from in situ capacitance experiments to physical mechanisms

Multilayer ceramic capacitors, as critical components in aerospace applications, demand thorough reliability assessment under gamma ray irradiation in extreme environments. While previous studies predominantly employed ex situ high-dose-rate radiation methods, significant knowledge gaps remain regarding dose-rate dependencies, particularly at lower levels. This investigation pioneers comprehensive in situ capacitance experimentation with controlled dose-rate variations coupled with multiscale structural characterization spanning from average to state-of-the-art atomic-scale probing. Our findings reveal three distinct radiation response mechanisms in BaTiO₃-based MLCCs: (i) classical total ionizing dose effects, (ii) enhanced low dose rate sensitivity effect, and (iii) an intriguing partial self-recovery effect. Through a systematic evaluation of collision dynamics, defect evolution pathways, and microstructural transformations, we report that radiation-induced modifications in defect concentration and spatial distribution fundamentally govern charge trapping efficiency and domain wall pinning behavior. These microstructural alterations ultimately dictate the macroscopic manifestation of the effects of gamma radiation degradation.