Electronic and Magnetic Properties of Ultrathin Au/Pt Nanowires
journal contributionposted on 09.09.2009, 00:00 by Xiaowei Teng, Mikhail Feygenson, Qi Wang, Jiaqing He, Wenxin Du, Anatoly I. Frenkel, Weiqiang Han, Meigan Aronson
We have reported the synthesis of Au25Pt75 and Au48Pt52 alloyed ultrathin nanowires with average widths of less than 3 nm via a wet chemistry approach at room temperature. Using a combination of techniques, including scanning transmission electron microscopy equipped with X-ray energy dispersive spectroscopy, ultraviolet−visible spectroscopy, and X-ray absorption near-edge structure and extended X-ray absorption fine structure spectroscopies, we identified the stoichiometry-dependent heterogeneous crystalline structures, as well as electronic structures with respect to the charge transfer between Pt and Au within both nanowires. In particular, we observed d-charge depletion at the Au site and the d-charge gain at the Pt site in Au48Pt52 nanowires, which accounted for its ferromagnetic magnetic behavior, in contrast to the paramagnetism and diamagnetism appearing respectively in bulk Pt and Au.