Search

This paper describes the synthesis and magnetic properties of multifunctional Fe3O4-AuPt core-shell nanoparticles. The Fe3O4-Au Pt core-shell nanoparticles were synthesized by a one-pot polyol process in two consecutive steps from Fe, Au, and Pt precursors. The structural characterization and property analysis proves the formation of the core-shell nanostructure fusing the multifunctionality in a single entity. The TEM observation shows that the Fe3O4-AuPt core-shell nanoparticles are highly crystalline and uniform in size distribution, with an averaged particle size of ~12.5 nm in diameter, whereas the X-ray diffraction patterns provide further substantiation. The surface plasmon resonance arising from the AuPt nano-shell was revealed by UV-vis spectroscopy, while the magnetic measurements by YSM and PPMS demonstrate the well-defined superparamagnetic and/or soft-ferromagnetic behavior of the Fe3O4-AuPt core-shell nanoparticles. [ABSTRACT FROM AUTHOR]

Multifunctional Au0.5Fe0.5 alloy nanoparticles from a polyol process were investigated, showing the alloy nanostructures with the formation of a new phase and twin microstructures. Giant diamagnetism, on the order of -10-2 emu g-1 Oe-1, is observed in the zero-field cooled process of the nanoparticles, which is modeled in terms of the spin-orbital interactions tuned by the modified potential energy as a result of the shrinking dimension, peculiar disordered microstructure, and heterogeneous elemental composition. [ABSTRACT FROM AUTHOR]

Au-doped CoPt nanowires were prepared in anodized aluminum oxide (AAO) nanotemplates by electrodeposition and the doping effects on their microstructure and magnetic properties were investigated. Dependent on the deposition conditions, the CoPtAu nanowires can have the cubic or tetragonal phase. The magnetic measurements indicate that the nanowires demonstrate ferromagnetic behavior, showing the easy axis along the direction of the nanowires and strong enhancement in coercivity and squareness prior to annealing, whereas the optical measurements reveal plasmon resonances characteristic of nanostructured Au. [ABSTRACT FROM AUTHOR]

We report the synthesis and characterization of Fe - FeOx core-shell nanowires by thermal conversion of the Fe nanowires from pulse electrodeposition in anodized aluminum oxide (AAO) nanotemplates under various conditions. Well-defined core-shell nanostructure of the Fe - FeOx nanowires was confirmed by TEM and corresponding elemental line scanning and point scanning. The type of the iron oxide in the shell was identified using nano-Raman spectroscopy, which exposes magnetite to be the major constituent. The magnetic measurements demonstrate that the nanowires are robustly soft magnetic, with the magnetization tunable by heat treatment parameters and a weak magnetic easy direction parallel to the nanowire axis. [ABSTRACT FROM AUTHOR]