Electron Small Polarons and Their Mobility in Iron (Oxyhydr)oxide Nanoparticles

Abstract

Iron Hopping: Iron oxide minerals shuttle electrons around in a wide range of biogeochemical processes. Katz et al. (p. 1200 ) used time-resolved x-ray absorption spectroscopy to take a closer look at how this happens. By using photoionized surface dyes to inject electrons into three different solid oxide phases, they found that electrons hop among iron centers at rates that depend more on structure in their immediate vicinity than on the extended ordering of the crystal lattice. These observations bolster the prevailing small polaron model in which charge carriers associate closely with individual metal sites.