In-situ transmission electron microscopic study of perovskite-type niobate nanosheets under electron-irradiation and heating

In-situ transmission electron microscopic (TEM) observation has been performed in the study of effects of electron irradiation and heating on the perovskite-type (TBA, H)Ca2Nb3O10 nanosheet material. Radiation-induced migration of vacancies was found to play an important role in the generation of various structural defects under electron irradiation at room temperature. Irradiation-induced defects include loops and stacking fault pyramids (SFP). SFPs are the new structural features since they neither have been discovered in bulk perovskite materials nor have been generated as extended defects under irradiation. Extraction of interlayer molecules via thermal dynamic effects of electron illumination has produced a variety of domain boundaries including antiphase boundaries, delta-boundaries, and amorphous interfaces due to irradiation damage. The present nanosheet material has also been heated to similar to500 degreesC during the in-situ TEM observation. Periodic antiphase domain boundary structures have been observed after heating.