title: Coexistence of two different Cr ions by self-doping in half-metallic CrO2 nanorods.
abstract: We investigated the physical properties of Cr ions in half-metallic CrO(2) using 53Cr nuclear magnetic resonance (NMR). The 53Cr NMR spectra showed two peaks with a similar intensity instead of the single peak anticipated from a uniform single valence Cr(+4). Both Cr peaks exhibited a strong anisotropy in the hyperfine field and similar values in the enhancement factor and T2 relaxation time. These results suggest the coexistence of two different Cr ions (provisionally, Cr(+4 +/- 1/3)) by a self-doping effect, which is a likely origin of the metallic ferromagnetism in CrO(2).
authors.affiliation: Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea.
authors.forename: Jeong Hyun
authors.initials: JH
authors.lastname: Shim
authors.forename: Soonchil
authors.initials: S
authors.lastname: Lee
authors.forename: Joonghoe
authors.initials: J
authors.lastname: Dho
authors.forename: Do-Hyung
authors.initials: DH
authors.lastname: Kim