Choi, Haneul Lee, Gwangyeob Roh, Jong Wook Park, Jin-Woo Chang, Hye Jung 2024-01-19T11:32:40Z 2024-01-19T11:32:40Z 2022-06-02 2022-08 0957-4484 https://pubs.kist.re.kr/handle/201004/114846 Dielectric two-dimensional oxide nanosheets are attractive because of their thermal stability and high-k property. However, their atomic structure characterization has been limited since they are easily degraded by electron-beams. This study aimed to investigate the electron-beam induced damage mechanisms for exfoliated Ca2Na2Nb5O16 (CNNO) nanosheets. Knock-on damage dominantly occurred at high voltages, leaving short-range order in the final amorphous structure. On the other hand, a series of chemical reactions predominantly occurred at low voltages, resulting in random elemental loss and a fully disordered amorphous structure. This radiolysis was facilitated by insulated CNNO nanosheets that contained a large number of dangling bonds after the chemical solution process. The radiolysis damage kinetics was faster than knock-on damage and induced more elemental loss. Based on our understanding of the electron beam-induced degradation, atomic-scale imaging of the CNNO nanosheets was successfully performed using Cs-corrected scanning transmission electron microscopy at 300 keV with a decreased beam current. This result is of particular significance because understanding of electron-beam damage in exfoliated and insulating 2D oxide sheets could improve identification of their atomic structure using electron microscopy techniques and lead to a practical guide for further extensive characterization of doped elements and layered structures to improve their properties. English Institute of Physics Publishing Electron-beam induced damage process for Ca2Na2Nb5O16 nanosheets Article 10.1088/1361-6528/ac6bae 1 Nanotechnology, v.33, no.32 Nanotechnology 33 32 N scie scopus 000797668700001 Nanoscience & Nanotechnology Materials Science, Multidisciplinary Physics, Applied Science & Technology - Other Topics Materials Science Physics Article RADIATION-DAMAGE TITANIA NANOSHEETS OXIDE NANOMATERIALS ENHANCEMENT PHASE LAYER 2D nanosheets perovskite oxide radiation damage transmission electron microscope