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Preparation of highly magnetic air-stable nanocrystalline materials

Objective

Magnetic nanoparticles may have important applications in magnetic data storage and recording, xerography, magnetic resonance imaging, ultra sensitive magnetic biosensors and drug delivery systems. Thus, the synthesis of magnetic nanoparticles with controlled magnetic properties, particle size and structure is a challenge in material science. Magnetic particles available have magnetization of 20-50 emu/g or less. Iron nanoparticles have the highest magnetization values. Yet, conventional Fe nanosized particles are unstable with respect to oxidation. NANOMAG aims to develop air-stable Fe nanoparticles with very high magnetization, close to or higher than that of bulk Fe (220 emu/gr). We will combine 2 approaches (coating of Fe nanoparticles with polymers & coating with carbon). Sonolysis of Fe pentacarbonyl in a specific solvent, able to generate in situ polymeric material will be applied. This will be followed by the thermal treatment of the obtained iron-polymer nanocomposite to prepare stable Fe nanoparticles. Magnetic nanoparticles may have important applications in magnetic data storage and recording, xerography, magnetic resonance imaging, ultra sensitive magnetic biosensors and drug delivery systems. Thus, the synthesis of magnetic nanoparticles with controlled magnetic properties, particle size and structure is a challenge in material science. Magnetic particles available have magnetization of 20-50 emu/g or less. Iron nanoparticles have the highest magnetization values. Yet, conventional Fe nanosized particles are unstable with respect to oxidation. NANOMAG aims to develop air-stable Fe nanoparticles with very high magnetization, close to or higher than that of bulk Fe (220 emu/gr). We will combine 2 approaches (coating of Fe nanoparticles with polymers & coating with carbon). Sonolysis of Fe pentacarbonyl in a specific solvent, able to generate in situ polymeric material will be applied. This will be followed by the thermal treatment of the obtained iron-polymer nanocomposite to prepare stable Fe nanoparticles.

OBJECTIVES
We consider the following criteria as the main objectives of this project:
(1) to reach a situation in which by controlling the experimental parameters we will be able to "tailor" magnetic properties of final nanocrystalline material;
(2) to prepare the material with saturation of magnetization of 240 emu/gr and coercivity of 10-30 Oe at the first stage of the project;
(3) to obtain air-stable iron nanoparticles having almost the same saturation of magnetization and a coercivity equal or even less than 5 Oe at the final stage of the project.

DESCRIPTION OF WORK
1) Tailoring magnetic and coercivity properties: The sonochemical reaction will be carried out in a glass cell whose volume is 100 ml. The temperature of the cell will be thermo stated and controlled. The reaction will be carried out under 1.1 atmospheres of argon. As mentioned above the time will be one of the variables of importance and it will be varied between 1-5 hours. The FE(CO)5, in diphenyl methane will be varied over the range of 0.005 M to 0.5 M. The annealing temperature will be varied 400-800° C. In the separation, washing, and drying of products we will follow a well-known routine. The products will undergo annealing before the examination of their morphological and compositional characterization;

2) Specifications and Characterizations of the products. The morphological tests will include TEM, SEM, and AFM measurements. The compositional characterization will include XRD, elemental analysis, and FTIR. The materials will be mailed to Denmark where the magnetization measurements will be carried out. They will include: Mössbauer spectroscopy, and magnetization loop measurements.

Funding Scheme

ACM - Preparatory, accompanying and support measures

Coordinator

BAR ILAN UNIVERSITY
Address
Bar Ilan University Campus
52900 Ramat Gan
Israel

Participants (1)

DANMARKS TEKNISKE UNIVERSITET
Denmark
Address
Anker Engelundsvej 1, Bygning 101A
2800 Kgs. Lyngby