Korean Journal of Metals and Materials (대한금속재료학회지)

The Korean Institute of Metals and Materials (대한금속재료학회)
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Real-time Transformation of FePt Nanoparticles to L10 Phase by the Gas Phase Synthesis

기상합성공정을 이용한 FePt 나노입자의 실시간 L10 상변화

  • Lee, Ki-Woo (Department of Metallurgy and Materials Science, Hanyang University) ;
  • Lee, Chang-Woo (Department of Metallurgy and Materials Science, Hanyang University) ;
  • Kim, Soon-Gil (Department of Metallurgy and Materials Science, Hanyang University) ;
  • Lee, Jai-Sung (Department of Metallurgy and Materials Science, Hanyang University)
  • 이기우 (한양대학교 금속재료공학과) ;
  • 이창우 (한양대학교 금속재료공학과) ;
  • 김순길 (한양대학교 금속재료공학과) ;
  • 이재성 (한양대학교 금속재료공학과)
  • Received : 2010.09.17
  • Published : 2011.01.25
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Abstract

Real-time formation of $L1_0$ phase of FePt nanoparticles in the gas phase during ultrasonic-spray pyrolysis is first discussed in the present study. Without any post heat treatment, $L1_0$ phase of FePt nanoparticles appeared at the temperature above $900^{\circ}C$ in the gas phase synthesis. X-ray diffractometry (XRD) and transmission electron microscopy (TEM) studies revealed that FePt nanoparticles less than 10 nm in size contained small volume of $L1_0$ fct phase. However, in other samples obtained at the temperature below $900^{\circ}C$, iron oxide phase co-existed and no evidence of phase transformation was found. Thus, it is anticipated that the time of flight of particles required for crystallization and phase transformation was extended according to the increase of the collision rate. Finally, magnetic properties represented by coercivity and saturation magnetization and functional groups on the particle surface were discussed based on VSM and FT-IR results.

Keywords

References

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