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Iron nanoparticles encapsulated by different shells have attracted wide attention of scientists and engineers because of their unique physical and chemical properties,such as magnetic,optical,catalytic,biomedical and electrical properties.The shells may be composed of graphitic layers,polymer,metal oxide,noble metal or different structures containing several elements [1,2].Such core-shell iron nanoparticles may be used for some applications,such as magnetic recording materials,catalysis,microwave absorption,drug delivery,lithium-ion batteries,etc [1-3].The methods to prepare such nanoparticles include hydrothermal reaction,chemical vapor deposition,spray pyrolysis,DC arc discharge,etc [3].In this work,we present the preparation of N-doped composite shell encapsulated Fe nanoparticles(NDCSEINPs)by DC arc discharge under nitrogen intake temperature of 800℃,using an anode with high Fe content and good homogeneity.The microstructure,composition and morphology of the products or NDCSEINPs were characterized by X-ray diffractometer(XRD),transmission electron microscope(TEM),high-resolution transmission electron microscope(HRTEM),energy dispersive X-ray(EDX)spectroscope and Electron Energy Loss Spectroscopy(EELS),respectively.The magnetic and optical properties were also investigated.The results reveal that the phase composition of the as-prepared NDCSEINPs contains graphitic carbon,iron,iron carbide(Fe3C),austenite(CFe15.1)and iron nitride(Fe3N); the cores consist of iron,Fe3C,CFe15.1 and Fe3N; and the shells are composed of homogeneously amorphous structure containing C,Fe,O and N elements.As far as we know,no such composite shells have been reported.With such shells,the performance of antioxidation of the Fe-core will be improved remarkably,and the field of application of the as-prepared NDCSEINPs may be expanded further,especially under the conditions of the environment of high temperature and no protective atmosphere.