Atomic-scale 3D imaging of individual dopant atoms in a complex oxide

TL;DR

This paper demonstrates atomic-scale 3D imaging of individual dopant atoms in a complex oxide using atom-probe tomography, revealing precise dopant positions and distributions crucial for understanding local structure-property relationships.

Contribution

It introduces a method to visualize and analyze individual dopant atoms in complex oxides at atomic resolution, enabling detailed study of dopant effects on material properties.

Findings

Ti atoms are located within Mn layers without clustering

APT provides quantitative dopant distribution at unit cell level

High-resolution 3D maps reveal dopant positions in complex oxides

Abstract

A small percentage of dopant atoms can completely change the physical properties of the host material. For example, chemical doping controls the electronic transport behavior of semiconductors and gives rise to a wide range of emergent electric and magnetic phenomena in oxides. Imaging of individual dopant atoms in lightly doped systems, however, remains a major challenge, hindering characterization of the site-specific effects and local dopant concentrations that determine the atomic-scale physics. Here, we apply atom-probe tomography (APT) to resolve individual Ti atoms in the narrow band gap semiconductor ErMnO3 with a nominal proportion of 0.04 atomic percent. Our 3D imaging measures the Ti concentration at the unit cell level, providing quantitative information about the dopant distribution within the ErMnO3 crystal lattice. High-resolution APT maps reveal the 3D lattice position of individual Ti atoms, showing that they are located within the Mn layers with no signs of clustering or other chemical inhomogeneities. The 3D atomic-scale visualization of individual dopant atoms provides new opportunities for the study of local structure-property relations in complex oxides, representing an important step toward controlling dopant-driven quantum phenomena in next-generation oxide electronics.