Oxygen vacancies, especially their distribution, are directly coupled to the electromagnetic properties of oxides and related emergent functionalities that have implication in device applications. Here using a homoepitaxial strontium titanate thin film, we demonstrate a controlled manipulation of the oxygen vacancy distribution using the mechanical force from a scanning probe microscope tip. By combining Kelvin probe force microscopy imaging and phase-field simulations, we show that oxygen vacancies can move under a stress-gradient-induced depolarisation field. When tailored, this nanoscale flexoelectric effect enables a controlled spatial modulation. In motion, the scanning probe tip thereby deterministically reconfigures the spatial distribution of vacancies. The ability to locally manipulate oxygen vacancies on-demand provides a tool for the exploration of mesoscale quantum phenomena, and engineering multifunctional oxide devices.
@article{arxiv.1709.07201,
title = {Controlled manipulation of oxygen vacancies using nanoscale flexoelectricity},
author = {Saikat Das and Bo Wang and Ye Cao and Myung Rae Cho and Yeong Jae Shin and Sang Mo Yang and Lingfei Wang and Minu Kim and Sergei V. Kalinin and Long-Qing Chen and Tae Won Noh},
journal= {arXiv preprint arXiv:1709.07201},
year = {2017}
}
Comments
35 pages, Main text and the supplementary information combined