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        검색결과 5

        1.
        2010.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Multi shell graphite coated Ag nano particles with core/shell structure were successfully synthesized by pulsed wire evaporation (PWE) method. Ar and (10 vol.%) gases were mixed in chamber, which played a role of carrier gas and reaction gas, respectively. Graphite layers on the surface of silver nano particles were coated indiscretely. However, the graphite layers are detached, when the particles are heated up to in the air atmosphere. In contrast, the graphite coated layer was stable under Ar and atmosphere, though the core/shell structured particles were heated up to . The presence of graphite coated layer prevent agglomeration of nanoparticles during heat treatment. The dispersion stability of the carbon coated Ag nanoparticles was higher than those of pure Ag nanoparticles.
        4,000원
        2.
        2009.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Carbon-coated Cu nanopowders with core/shell structure have been successfully fabricated by pulsed wire evaporation (PWE) method, in which a mixed gas of Ar/ (10 vol.%) was used as an ambient gas. The characterization of the samples was carried out using x-ray diffraction (XRD), scanning electron microscope (SEM), and high resolution transmission electron microscope (HRTEM). It was found that the nanoparticles show a spherical morphology with the size ranging of 10-40 nm and are covered with graphite layers of 2-4 nm. When oxygen-passivated Cu nanopowders were annealed under flowing argon gas (600 and 800), the crystallinity of phase and the particle size gradually increased. On the other hand, carbon-coated Cu nanopowders remained similar to as-prepared case with no additional oxide or carbide phases even after the annealing, indicating that the metal nanoparticles are well protected by the carbon-coating layers.
        4,000원
        3.
        2007.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The magnetic alloys of Cu-Fe () were prepared by a mechanical alloying method and their structural and magnetic behaviors were examined by X-ray diffraction and Mossbauer spectra. The magnetization curves did not distinctly show the saturation at 70 kOe for the concentrated alloys of . The Mossbauer spectrum of at room temperature shows one Lorentzian line of the paramagnetic phase, whereas the Mossbauer spectrum of consists of sextet Lorentzian line at room temperature and a centered doublet line. The Mossbauer spectra of measured in the temperature ranges from 13 to 295 K, implies that to consists of two magnetic phases. One superimposed sextet corresponds to the ferromagnetic iron in Cu and the other one indicates the superparamagnetic iron rich phase.
        3,000원