Electron-Beam Writing of Atomic-Scale Reconstructions at Oxide Interfaces

TL;DR

This paper presents a precise electron-beam writing technique to create atomically sharp interfaces in oxide membranes, enabling new heterostructure fabrication beyond traditional epitaxial methods.

Contribution

A novel method for atomic-scale writing of oxide interfaces across membranes, expanding possibilities for materials design and heterostructure engineering.

Findings

Achieved atomically sharp interface reconstructions between SrTiO3 membrane and substrate.

Demonstrated localized electron-beam exposure can precisely modify oxide structures.

Enabled new strategies for fabricating functional oxide heterostructures.

Abstract

The epitaxial growth of complex oxides enables the production of high-quality films, yet substrate choice is restricted to certain symmetry and lattice parameters, thereby limiting the technological applications of epitaxial oxides. In comparison, the development of free-standing oxide membranes gives opportunities to create novel heterostructures by non-epitaxial stacking of membranes, opening new possibilities for materials design. Here, we introduce a method for writing, with atomic precision, ionically bonded crystalline material across the gap between an oxide membrane and a carrier substrate. The process involves a thermal pre-treatment, followed by localized exposure to the raster scan of a scanning transmission electron microscopy (STEM) beam. STEM imaging and electron energy-loss spectroscopy show that we achieve atomically sharp interface reconstructions between a 30 nm-thick SrTiO${_3}$ membrane and a niobium-doped SrTiO${_3}$(001)-oriented carrier substrate. These findings indicate new strategies for fabricating synthetic heterostructures with novel structural and electronic properties.