Large‐Scale Synthesis of Uniform and Crystalline Magnetite Nanoparticles Using Reverse Micelles as Nanoreactors under Reflux Conditions

We have synthesized uniform and highly crystalline magnetite nanoparticles from the reaction of iron salts in microemulsion nanoreactors. The particle size can be controlled from 2 nm to 10 nm by varying the relative concentrations of the iron salts, surfactant, and solvent. Transmission electron microscope images of the nanoparticles reveal that they are very uniform in size distribution. Structural characterization using X‐ray diffraction and X‐ray magnetic circular dichroism shows that the nanoparticles are magnetite. The magnetic characterization of the nanoparticles showed that they are superparamagnetic at room temperature. Using a similar synthetic procedure, we have been able to synthesize nanoparticles of several mixed metal ferrites including cobalt ferrite, manganese ferrite, nickel ferrite, and zinc ferrite.

[1]  R. Wang.  Nanoparticles: from theory to application: Günter Schmid (ed), WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim, ISBN 3-527-30507-6, Hbk, 444 pages, price 159,00 Euro , 2005 .

[2]  Taeghwan Hyeon,et al.  Ultra-large-scale syntheses of monodisperse nanocrystals , 2004, Nature materials.

[3]  P. Fejes,et al.  Superlattices of Iron Nanocubes Synthesized from Fe[N(SiMe3)2]2 , 2004, Science.

[4]  C. Batich.  BOOK REVIEW: Scientific and Clinical Applications of Magnetic Carriers, edited by U. Häfeli, W. Schütt, J. Teller, and M. Zborowski , 1998, Annals of Biomedical Engineering.

[5]  Kisay Lee,et al.  Detection of giardia lamblia cysts by polymerase chain reaction (PCR) coupled with immunomagnetic separation (IMS) , 2004 .

[6]  K.-S. Cho,et al.  Three-dimensional binary superlattices of magnetic nanocrystals and semiconductor quantum dots , 2003, Nature.

[7]  L. Brus,et al.  Magnetite Fe3O4 Nanocrystals: Spectroscopic Observation of Aqueous Oxidation Kinetics† , 2003 .

[8]  Taeghwan Hyeon,et al.  Chemical synthesis of magnetic nanoparticles. , 2003, Chemical communications.

[9]  M. Pileni.  The role of soft colloidal templates in controlling the size and shape of inorganic nanocrystals , 2003, Nature materials.

[10]  H. Jang,et al.  Preparation of Cobalt Nanoparticles in the Gas Phase (I): Kinetics of Cobalt Dichloride Reduction , 2003 .

[11]  C. Serna,et al.  Magnetic Behavior of γ-Fe2O3 Nanocrystals Dispersed in Colloidal Silica Particles , 2003 .

[12]  Hao Zeng,et al.  Exchange-coupled nanocomposite magnets by nanoparticle self-assembly , 2002, Nature.

[13]  A. Rogach,et al.  Organization of Matter on Different Size Scales: Monodisperse Nanocrystals and Their Superstructures , 2002 .

[14]  R. Tannenbaum,et al.  Shape Control of Iron Oxide Nanoclusters in Polymeric Media , 2002 .

[15]  Pedro Tartaj,et al.  Microemulsion-Assisted Synthesis of Tunable Superparamagnetic Composites , 2002 .

[16]  Hao Zeng,et al.  Size-controlled synthesis of magnetite nanoparticles. , 2002, Journal of the American Chemical Society.

[17]  B. Park,et al.  Synthesis of Highly Crystalline and Monodisperse Cobalt Ferrite Nanocrystals , 2002 .

[18]  Andreas Kornowski,et al.  Self-assembly of ZnO: from nanodots to nanorods. , 2002, Angewandte Chemie.

[19]  Taeghwan Hyeon,et al.  Synthesis of highly crystalline and monodisperse maghemite nanocrystallites without a size-selection process. , 2001, Journal of the American Chemical Society.

[20]  Suresh C. Pillai,et al.  Preparation of magnetic nanoparticles and their assemblies using a new Fe(II) alkoxide precursor , 2001 .

[21]  R. Lerner,et al.  Activation Volumes for Solid-Solid Transformations in Nanocrystals , 2001, Science.

[22]  Gil Markovich,et al.  Ordered Two‐Dimensional Arrays of Ferrite Nanoparticles , 2001 .

[23]  T. Sugimoto.  CHAPTER 7 – MONODISPERSED SYSTEMS , 2001 .

[24]  M. Pileni,et al.  Assemblies of Ferrite Nanocrystals: Partial Orientation of the Easy Magnetic Axes , 2001 .

[25]  H. Chan,et al.  Synthesis of Fe3O4 nanoparticles from emulsions , 2001 .

[26]  Martyn Poliakoff,et al.  The continuous hydrothermal synthesis of nano-particulate ferrites in near critical and supercritical water , 2001 .

[27]  Peter Michler,et al.  Quantum correlation among photons from a single quantum dot at room temperature , 2000, Nature.

[28]  A. Gedanken,et al.  Sonochemical synthesis and characterization of pure nanometer-sized Fe3O4 particles , 2000 .

[29]  Sun,et al.  Monodisperse FePt nanoparticles and ferromagnetic FePt nanocrystal superlattices , 2000, Science.

[30]  M. Pileni,et al.  Nanoparticles of Cobalt Ferrite: Influence of the Applied Field on the Organization of the Nanocrystals on a Substrate and on Their Magnetic Properties , 2000 .

[31]  Z. John Zhang,et al.  Reverse Micelle Synthesis and Characterization of Superparamagnetic MnFe2O4 Spinel Ferrite Nanocrystallites , 2000 .

[32]  M. Pileni,et al.  Nonstoichiometric Zinc Ferrite Nanocrystals: Syntheses and Unusual Magnetic Properties , 2000 .

[33]  A. P. Alivisatos,et al.  A new nonhydrolytic single-precursor approach to surfactant-capped nanocrystals of transition metal oxides , 1999 .

[34]  Sabino Veintemillas-Verdaguer,et al.  Surface and Internal Spin Canting in γ-Fe2O3 Nanoparticles , 1999 .

[35]  Shouheng Sun,et al.  Synthesis of monodisperse cobalt nanocrystals and their assembly into magnetic superlattices (invited) , 1999 .

[36]  B. Chu,et al.  Preparation and Properties of Magnetite and Polymer Magnetite Nanoparticles , 1999 .

[37]  Janos H. Fendler,et al.  Nanoparticles and Nanostructured Films , 1998 .

[38]  R. Kodama,et al.  Finite Size Effects in Antiferromagnetic NiO Nanoparticles , 1997 .

[39]  B. G. Searle,et al.  Fe L2,3 linear and circular magnetic dichroism of Fe3O4 , 1997 .

[40]  I. J. Jang,et al.  Ordered structures in Fe3O4 kerosene-based ferrofluids , 1997 .

[41]  S. Chikazumi.  Physics of ferromagnetism , 1997 .

[42]  Pieter Stroeve,et al.  Synthesis and Characterization of Nanometer-Size Fe3O4 and γ-Fe2O3 Particles , 1996 .

[43]  Diandra L. Leslie-Pelecky,et al.  Magnetic Properties of Nanostructured Materials , 1996 .

[44]  A. Alivisatos.  Semiconductor Clusters, Nanocrystals, and Quantum Dots , 1996, Science.

[45]  R. S. Sapieszko.  Preparation of well-defined colloidal particles by thermal decomposition of metal chelates. I. Iron oxides*1 , 1980 .