Relaxation of transport properties in electron doped SrTiO3

TL;DR

This study investigates how electron doping via Ar+ irradiation affects the transport properties of SrTiO3, revealing time-dependent relaxation likely due to oxygen vacancy diffusion with an activation energy around 1 eV.

Contribution

It demonstrates that oxygen vacancy diffusion causes relaxation in transport properties of electron-doped SrTiO3, providing insights into defect dynamics in this material.

Findings

Carrier mobility similar to other electron-doped SrTiO3 systems.

Sheet resistance increases over time with a temperature-dependent rate.

Relaxation attributed to oxygen vacancy diffusion with ~1 eV activation barrier.

Abstract

We electron-dope single crystal samples of SrTiO_3 by exposing them to Ar^+ irradiation and observe carrier mobility similar in its magnitude and temperature dependence to the carrier mobility in other electron-doped SrTiO3 systems. We find that some transport properties are time-dependent. In particular, the sheet resistance increases with time at a temperature-dependent rate, suggesting an activation barrier on the order of 1 eV. We attribute the relaxation effects to diffusion of oxygen vacancies - a process with energy barrier similar to the observed activation energy.