Characterization of nanocrystalline CuxFe1−xFe2O4 ferrite powders synthesized via plasma arc discharge process

The nano-sized Fe powders were prepared by plasma arc discharge (PAD) process using pure Fe rod. The microstructure of the prepared nanopowders was evaluated and the effect of hydrogen gas in the chamber atmosphere was investigated. In addition, the sintering behavior of nanosized Fe powders was analyzed and compared with those of conventional micron powders. The prepared Fe nanopowders had nearly spherical shapes and consisted of metallic core and oxide shell structures. In PAD nanopowder sintering, the higher volume shrinkage at low sintering temperature was observed due to the reduction of surface oxide. The PAD nanopowders showed 6 times higher densification rate and more significant isotropic shrinkage behavior than those of micron sized Fe powders.

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Characteristics of Fe Nano Powders Synthesized by Plasma Arc Discharge Process

Korean Journal of Materials Research ◽

10.3740/mrsk.2004.14.7.511 ◽

2004 ◽

Vol 14 (7) ◽

pp. 511-515 ◽

Cited By ~ 2

Author(s):

Woo-Young Park ◽

Cheol-Su Youn ◽

Ji-Hun Yu ◽

Young-Woo Oh ◽

Chul-Jin Choi

Keyword(s):

Arc Discharge ◽

Discharge Process ◽

Plasma Arc ◽

Plasma Arc Discharge

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Synthesis and Characterization of FeCoNiAl Nanocapsules by Plasma arc Discharge Process

Journal of Materials Research ◽

10.1557/jmr.2005.0304 ◽

2005 ◽

Vol 20 (9) ◽

pp. 2534-2543 ◽

Cited By ~ 13

Author(s):

Dian-Yu Geng ◽

Woo-Young Park ◽

Jin-Chun Kim ◽

Ji-Hun Yu ◽

Chul-Jin Choi ◽

...

Keyword(s):

Magnetic Properties ◽

Transition Metal ◽

Surface Composition ◽

Arc Discharge ◽

Binding Energies ◽

The Body ◽

Cubic Phase ◽

Discharge Process ◽

Plasma Arc ◽

Plasma Arc Discharge

A series of magnetic FeCoNiAl nanocapsules was synthesized by the plasma arc discharge method; the targets of Fe, Co, Ni, and Al powders were changed with varying compositions. The compositions of the nanocapsules were found to be quite different from those of the corresponding targets; the relative amount of Al (or Ni, Co) to Fe was increased (or decreased). Structures, particles sizes, composition, surface composition, magnetic properties, and thermal stability of the nanocapsules were investigated. The saturation magnetization Ms = 106.8 emu/g and coercive force iHc = 367 Oe were achieved for the nanocapsules with the Fe62.5Co21Ni13Al2.5 target. In the FeCoNiAl nanocapsules, the binding energies of Fe, Co, and Ni were different from those of the metals Fe, Co, and Ni. The binding energies of Fe2p3/2 and Fe2p1/2 of the nanocapsules were 708.2 and 721.3 eV, respectively. The four-layer structure was proposed to give a clear statement of how the composition and phase varied radially in the nanocapsules. The major contents of the four layers—i.e., the outer shell, the inner shell, the outer core and the inner core—were amorphous alumina, crystalline alumina, transition metal oxides, and transition metal alloy, respectively. The compositions, structures, particle size, and grain size of the nanocapsules all affect their magnetic properties. In the FeCoNiAl nanocapsules, the greater th amount of the body-centered-cubic phase, the stronger the ferromagnetic magnetic properties.

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