Dislocation-enhanced electrical conductivity in rutile TiO 2 accessed by room-temperature nanoindentation

Dislocation-enhanced electrical conductivity is an emerging topic for ceramic oxides. In contrast to the majority of present studies which focus on large-scale crystal deformation or thin film fabrication to introduce dislocations, we use a nanoindentation pop-in stop method to locally generate ( 011 ) edge-type dislocations at room temperature, without crack formation, on the (100) surface of a rutile TiO 2 singlecrystal. Ion beam assisted deposition of microcontacts allowed for both deformed and non-deformed zones to be locally probed by impedance spectroscopy. Compared to the dislocation-free region, a local enhancement of the electrical conductivity by 50% in the dislocation-rich regions is found. The study paves the way for local mechanical-doping of ceramics and oxide materials, allowing for the use of dislocations to tune the local conductivity with high spatial resolution. (c) 2022 The Author(s). Published by Elsevier Ltd on behalf of Acta Materialia Inc. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ )

Automated summary

Dislocation-enhanced electrical conductivity is an emerging topic in ceramic oxides. Using a nanoindentation pop-in stop method, researchers have successfully generated (011) edge-type dislocations at room temperature on the (100) surface of a rutile TiO2 single crystal. The study found a local enhancement of electrical conductivity by 50% in the dislocation-rich regions compared to the dislocation-free region. This research opens up new possibilities for locally tuning the conductivity of ceramics and oxide materials using dislocations with high spatial resolution.