Thermal Plasma Synthesis of Superparamagnetic Iron Oxide Nanoparticles
Superparamagnetic iron oxide nanoparticles were synthesized by injecting ferrocene vapor and oxygen into an argon/helium DC thermal plasma. Size distributions of particles in the reactor exhaust were measured online using an aerosol extraction probe interfaced to a scanning mobility particle sizer, and particles were collected on transmission electron microscopy (TEM) grids and glass fiber filters for off-line characterization. The morphology, chemical and phase composition of the nanoparticles were characterized using TEM and X-ray diffraction, and the magnetic properties of the particles were analyzed with a vibrating sample magnetometer and a magnetic property measurement system. Aerosol at the reactor exhaust consisted of both single nanocrystals and small agglomerates, with a modal mobility diameter of 8–9 nm. Powder synthesized with optimum oxygen flow rate consisted primarily of magnetite (Fe3O4), and had a room-temperature saturation magnetization of 40.15 emu/g, with a coercivity and remanence of 26 Oe and 1.5 emu/g, respectively.
KeywordsIron oxide Nanoparticles DC thermal plasma Magnetic properties
This research was primarily supported by the U.S. National Science Foundation under Award Numbers CBET-0730184 and CBET-1066343, and by the Minnesota Futures Grant Program. Parts of the characterization work were conducted at the College of Science and Engineering Characterization Facility and the Institute for Rock Magnetism at the University of Minnesota.
- 8.Cornell RM, Schwertmann U (2003) The iron oxides: structure, properties, reactions, occurrences and uses, 2nd edn. Wiley-VCH, Weinheim, GermanyGoogle Scholar
- 9.Ward J, Naik KS, Guthrie JA, Wilson D, Robinson PJ (1999) Radiol 210:459–466Google Scholar
- 10.Kumano S, Murakami T, Kim T, Hori M, Okada A, Sugiura T, Noguchi Y, Kawata S, Tomoda K, Nakamura H (2003) Am J Roentgen 181:1335–1339Google Scholar
- 14.Smolensky ED, Park HYE, Berquo TS, Pierre VC (2010) Contrast Media Mol Imaging 6:189–199Google Scholar
- 18.Yoshida T, Akashi K (1981) Trans Jpn Inst Met 22:371–378Google Scholar
- 34.Subramanian V, Baskaran R, Krishnan H (2009) Aerosol Air Qual Res 9:172–186Google Scholar
- 42.Zhang B (2007) Thermal plasma synthesis and photoinduced coating of aluminum nanoparticles. PhD thesis, Univ Minnesota, MinneapolisGoogle Scholar
- 65.Cullity BD, Graham CD (2009) Introduction to magnetic materials, 2nd edn. IEEE/Wiley, HobokenGoogle Scholar