A joint research team from the Institute of Metal Research (IMR) of the Chinese Academy of Sciences and the Songshan Lake Materials Laboratory has achieved precise control and real-time observation of atomic-scale structural transformations, a fundamental scientific challenge in atomic-scale manufacturing.

The study was published in Advanced Materials. 

Using transmission electron microscopy, the researchers captured the dynamic movements of tantalum atoms in KTaO₃ crystals and successfully induced a precise structural transformation into tungsten bronze (K₆Ta₁₀.₈O₃₀), identifying key controlling parameters in the process.

They achieved this transformation The researchers selectively "knocked out" potassium and oxygen atoms from KTaO₃ through controlled electron dose and displacement, generating vacancies that subsequently drove the migration of heavier tantalum atoms. This coordinated atomic motion ultimately transformed the material from a perovskite structure into a stable, tetragonal tungsten bronze phase under ambient conditions.

The work establishes an important scientific foundation for both "precision fabrication" and "clear observation" at the atomic scale. It reveals the atomic mechanisms of electron beam-induced atomic motion and structural transformation while pioneering a technical pathway for electron-beam-based atomic "sculpting".

Combined with low-dose phase-contrast imaging and density functional theory calculations, the researchers clearly elucidated the atomic migration pathways and underlying driving mechanisms. This work offers important theoretical and technical support for the atomic-level manufacturing of future functional oxide electronic devices.

a. Structural schematic of KTaO₃; b. Schematic of electron beam irradiation in STEM mode; c–l. Atomic motion and structural transformation under electron beam irradiation. (Image by IMR)