▎ 摘　　要

Development of composite materials that combine the superior electronic properties of graphene with magnetic functionality is highly desirable as can open new doors for graphene applications. However, attempts to grow such structures typically result in significantly reduced graphene quality due to processing required for the graphene formation and/or magnetic functionalization. We report a magnetic graphene material consisting of 2-5 graphene layers encapsulating magnetic nanoparticles, produced in one step without any chemical modification or post-treatment, using a dual-action ferrofluid catalyst/carbon chemical vapor deposition (CVD) precursor. The resulting composite exhibits high quality, as evidenced by Raman spectroscopy, since the properties of as grown-pure graphene are fully preserved, coupled to magnetic sensitivity, as evidenced by Mossbauer and magnetic measurements, originated from the encapsulated Fe-based nanoparticles. Notably, the material is stable due to particle encapsulation by the graphene layers, while the fabrication is simple and carried out by CVD which is widely used in the microelectronics industry thus favoring scalability towards applications that include magnetoelectronics, high-density data storage, magnetic nanodevices, and electrochemical energy storage and supply. (C) 2013 Published by Elsevier Ltd.