Fig. 5: Activation energy and temperature dependent oxygen vacancy diffusion.
From: High-speed mapping of surface charge dynamics using sparse scanning Kelvin probe force microscopy
ΔCPD maps after application of −8 V during 1 min at different times and for different temperatures: a 338 K, c 378 K and e 418 K. b, d, f Corresponding profiles along the dashed black line over time. g ΔCPD evolution averaged over the central region (dashed squares in (a) at 3 different temperatures. h Arrhenius-type fit to obtain EA. i DFT calculated external electric field-dependent formation energy of oxygen vacancies on a (110) TiO2 rutile surface. The surface vacancy (VO1, or 0.0 Å) is marked in red, nearest subsurface vacancy (VO2, or 2.6 Å) in green, and deeper vacancy (VO3, or 5.0 Å) in blue. The distance reported is distance from the surface.
