Synthesis and characterization of FeAl nanoparticles by flow-levitation method

CHEN Shan-jun(陈善俊)^1,2,3, CHEN Yan(陈艳)^1,3, TANG Yong-jian(唐永建)^2,3, LUO Bing-chi(罗炳池)³, Yi Zao(易早)³, WEI Jian-jun(韦建军)

(1. College of Physical Science and Technology, yangtze University, jingzhou 434023, China;
2. Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China;
3. Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900, China)

Abstract:the synthesis of high purity intermetallic FeAl nanoparticles using the flow-levitation (FL) method was reported. Iron and aluminium droplets were levitated stably at about 2 230 °C. The morphology, crystal structure and chemical composition of FeAl nanoparticles were investigated by transmission electron microscopy (TEM), high-resolution TEM, X-ray diffraction and energy dispersive spectrometry. The results show that the average particle size of these nanoparticles is about 34.5 nm. Measurements of the d-spacing from X-ray diffraction and electron diffraction studies confirm that the intermetallic nanoparticles have the same crystal structure (B2) as the bulk FeAl. A thin oxidation coating is formed around the particles when being exposed to air. Based on the XPS measurements, the surface coating of the FeAl nanoparticles is composed of Fe₂O₃ and FeAl₂O₄. Besides, hysteresis curve reveals that saturation magnetization (M_s) of FeAl is 1.66 A/m², and the coercivity is about 1.214´10³ A/m.

Key words:intermetallic compound; FeAl nanoparticles; flow-levitation method