Radiation-resilient ferroelectricity in Ce-doped HfO2 thin films under 60Co γ-ray irradiation

Ce-doped HfO₂ thin films exhibited excellent γ-ray radiation tolerance. • Stable ferroelectric performance was maintained after γ-ray irradiation. • Ce doping stabilized the ferroelectric orthorhombic phase. • Radiation-induced defect accumulation and domain-wall pinning were suppressed. • Ce doping significantly improved electrical reliability. HfO 2 -based ferroelectric thin films have emerged as promising candidates for next-generation non-volatile memories operating in extreme environments owing to their excellent CMOS compatibility, scalability, and robust ferroelectricity. However, ionizing radiation induces oxygen vacancies and charge traps that deteriorate polarization stability and device reliability, while the relationship between radiation-induced defects and polarization switching kinetics remains insufficiently understood. In this work, Hf 0.85 Ce 0.15 O 2 (HCO) ferroelectric thin films were fabricated via a sol–gel process, and their structural evolution, domain-switching kinetics, and memory reliability were systematically investigated under 60 Co γ-ray total ionizing dose (TID) irradiation ranging from 0 to 1000 krad(Si). The HCO films maintained a stable ferroelectric phase after irradiation, with the remanent polarization ( P r ) exhibiting only a slight variation from 19.914 to 20.107 μC cm −2 and the coercive field ( E c ) increasing marginally from 1.418 to 1.465 MV cm −1 . Piezoresponse force microscopy (PFM) confirmed reversible domain switching throughout the irradiation process, while kinetic analysis based on the Merz model revealed that the activation field increased only from 9.49 to 10.07 MV cm −1 (≈6%), indicating that domain-wall mobility was well preserved. Moreover, the leakage current density remained within the order of 10 −10 –10 −8 A cm −2 , accompanied by excellent electrical reliability. XPS analysis revealed only limited changes in the Ce valence state and oxygen chemical environment after irradiation, consistent with the overall structural and ferroelectric stability of the films. Based on these results, the stable Ce–O coordination is proposed to help maintain local lattice stability and mitigate the influence of irradiation-induced perturbations on polarization switching. This work provides new insights into the radiation-stability mechanism of HfO 2 -based ferroelectrics and offers a promising strategy for the design of highly reliable ferroelectric memories for aerospace and nuclear electronics.