title: Excited carrier dynamics of alpha-Cr2O3/alpha-Fe2O3 core-shell nanostructures.
abstract: In this work alpha-Cr(2)O(3)/alpha-Fe(2)O(3) core-shell polycrystalline nanostructures were synthesized by using alpha-Cr(2)O(3) nanoparticles as seed crystals during aqueous nucleation. The formation of alpha-Fe(2)O(3) polycrystallites on alpha-Cr(2)O(3) surfaces was confirmed by X-ray diffraction, transmission electron microscopy, and energy-dispersive X-ray analysis. The excited-state relaxation dynamics of as-grown core-shell structures and "pure" alpha-Fe(2)O(3) particles of the same size were measured with femtosecond transient absorption spectroscopy. The results show the carrier lifetimes decay within a few picoseconds regardless of sample. This is likely due to fast recombination/trapping of carriers to defects and iron d-states.
authors.affiliation: Pacific Northwest National Laboratory, P.O. Box 999, K8-88, Richland, Washington 99352, USA.
authors.forename: Gang
authors.initials: G
authors.lastname: Xiong
authors.forename: Alan G
authors.initials: AG
authors.lastname: Joly
authors.forename: Gary P
authors.initials: GP
authors.lastname: Holtom
authors.forename: Chongmin
authors.initials: C
authors.lastname: Wang
authors.forename: David E
authors.initials: DE
authors.lastname: McCready
authors.forename: Kenneth M
authors.initials: KM
authors.lastname: Beck
authors.forename: Wayne P
authors.initials: WP
authors.lastname: Hess