Large Electric‐Field‐Induced Strain Close to the Surface in Barium Titanate Studied by Atomic‐Scale In Situ Electron Microscopy

With the use of in-situ scanning transmission electron microscopy, Yukio Sato and co-workers (article number 1900488) report the atomic-scale measurement of strain induced by applying electric fields in a ferroelectric. A precision of better than 1.3 pm was achieved in the lattice parameter measurement using the newly developed two-step affine transformation method. Unusually large increases in the lattice parameters of up to 7.0 pm were obtained near the edge of the barium titanate film. This study importantly demonstrates that small changes of lattice parameters by an electrical stimulus can now be detected on the basis of direct observation, which can accelerate the development of new electronic devices, batteries, and so on. Furthermore, local strain of a material can be modified by ion-beam process and an electric field.