化学法合成Fe,Al纳米粒子的研究.pdfVIP

Chem. Mater. 2007, 19, 1221 Articles Study of Magnetic FeAl Nanoparticles Synthesized Using a Chemical Route Dimple P. Dutta,*,† Garima Sharma,*,‡ A. K. Rajarajan,§ S. M. Yusuf,§ and G. K. Dey‡ Chemistry Diision, Materials Science Diision, and Solid State Physics Diision, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India Recei ed December 2, 2006. Reised Manuscript Receied January 15, 2007 In this paper we report the magnetic properties of nanosized intermetallic FeAl particles, prepared by a two-step chemical synthesis route and characterized using X-ray diffraction, conventional and high- resolution transmission electron microscopy (HRTEM), and energy dispersive X-ray spectroscopy (EDX) techniques. The nanoparticles have the same crystal structure (B2) as bulk FeAl. Atomic fringes of the FeAl nanocrystals were observed by using HRTEM. The particles were rectangular in shape with an average length of 2023 nm. The prepared nanoparticles are found to show magnetization with superparamagnetic behavior arising from the core as well as the surface of these particles. A wide distribution of blocking temperature is evident for these superparamagnetic particles. Introduction the application of oxide or copper coatings.8 Smaller grain size would lead to superior mechani