title: Stabilization mechanism of ZnO nanoparticles by Fe doping.
abstract: Surprisingly low solubility and toxicity of Fe-doped ZnO nanoparticles is elucidated on the basis of first-principles calculations. Various ZnO surfaces that could be present in nanoparticles are subject to substitutional Fe doping. We show that Fe stabilizes polar instable surfaces, while nonpolar surfaces, namely (101_0) and (112_0), remain intact. Polar surfaces can be stabilized indirectly through Fe2+-Fe3+ pair-assisted charge transfer, which reduces surface polarity and therefore, the solubility in polar solvents.
authors.affiliation: School of Engineering and Science, Jacobs University Bremen, Campus Ring 1, 28759 Bremen, Germany and Bremen Center for Computational Materials Science, Universität Bremen, Am Fallturm 1, 28359 Bremen, Germany.
authors.forename: Jianping
authors.initials: J
authors.lastname: Xiao
authors.affiliation: School of Engineering and Science, Jacobs University Bremen, Campus Ring 1, 28759 Bremen, Germany.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Kuc
authors.affiliation: Bremen Center for Computational Materials Science, Universität Bremen, Am Fallturm 1, 28359 Bremen, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Frauenheim
authors.affiliation: School of Engineering and Science, Jacobs University Bremen, Campus Ring 1, 28759 Bremen, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Heine