Magnetic nanoparticles have been known to have applications ranging from biomedicine (drug delivery, tumour treatment) to high density magnetic recording media, solar energy transformers, ferrofluids etc. Nanoparticles below a critical size are also reported to exhibit super-paramagnetic behavior as the particle becomes single magnetic domains.
        The properties of nanomaterials are expected to be between those of bulk and isolated atoms. The enhanced properties at nanoscale can be best utilized if local structural, electronic and magnetic properties are all well characterized. Combining spectroscopy and multi-harmonic magnetic susceptibility, we may open a plethora of opportunities for innovative materials. The non-linear electron dynamic transport processes and the structural spectroscopic analysis represents a new strategic approach that combines information on dynamic electronic properties and structural behavior of special significance in the characterization of nano-materials.
        X-ray absorption spectroscopy, namely EXAFS and XANES, allow investigating the structure and dynamics of nano-materials. Since these techniques look at the short range order, weakly ordered and even non-ordered materials can be studied. These spectroscopic methods provide a complete data on the type and number of atoms, ordering, inter-atomic distances, etc.
        Cobalt and alloys of cobalt (like FeCo) nanoparticles are being studied widely for their exceptional magnetic properties. Cobalt nanoparticles are soft materials with very high saturation magnetization, low coercivity, high permeability and high Curie temperature and can be used in turbine engine components, magnetic bearings etc. However, owing to their high surface area they are prone to oxidation and affecting its magnetization. Coating of cobalt nanoparticle by another material like platinum, silver may help minimizing this effect.
        In this project we planned to synthesize magnetic nanoparticles, especially of cobalt, by a thermal plasma process that is known to yield metastable crystalline phase. The synthesis parameters will be optimized to yield different size particles. The high thermal stresses developed in the nanomaterial during the synthesis results in a large number of free dangling bonds and large disorders at the grain boundaries. This is bound to change both the oxide formation of the cobalt nanoparticles as well as the magnetization values. Nanoparticles synthesized by thermal processes and its magnetization, oxidation levels etc. has never been characterized. Various reports in the literature mainly refer to wet chemical processes of synthesis or low temperature synthesis process. A few studies report the size dependent oxidation level of cobalt nanoparticles. The exact local atomic structure and the disorder need to be characterized by XAS spectroscopies (i.e., EXAFS and XANES) to identify the crystalline phases and their related magnetization. The stability of these nanostructures needs also to be characterized for each crystalline phase.
        The proposed work is planned to be carried out in three phases:
        · In the first phase pure cobalt nanoparticles of different sizes will be     synthesized and characterized.The results will be compared with the bulk cobalt material.
        · In the second phase the cobalt nanoparticles will be coated with silver nano-crystalline film in situ and the oxidation levels as well as the magnetization will be studied. Change in the local atomic structure will be characterized in great detail.
        · In the final phase cobalt nanoparticles will be grown on a patterned silicon substrate by magnetron sputtering process. This growth pattern will ensure a ordered formation of cobalt nanoparticles. On top of this a layer of silver nanoparticles will be deposited and the effects on magnetization and oxide formation will be studied.
        The Indian team will have a critical role in the synthesis of nanoparticles of various sizes and also carry out the initial characterization of morphology, crystallinity and magnetization.
        The Italian partners have a recognized expertise on X-ray Absorption Spectroscopy and magnetism and have also access to synchrotron radiation facilities that are essential for this project.
        Materials science and technology is a core area of research for many economies due to its potential contributions to manufacturing processes and innovative products. Asian nations and institutions are clearly focusing their research efforts on new materials, an area of research that has had a long tradition in India.
        The proposal following the signature of the India-Italy executive protocols of Scientific and Technological Cooperation between the Italian Republic and the Republic of India for the years 2012-2014 intends strengthening existing cooperation and triggering new ones with other Institutions in this large Asian country. The workshop will provide a learning opportunity and a fruitful exchange of ideas among highly qualified interdisciplinary teams. Indeed, this scientific event is aimed at promoting the scientific and technological Italian system involving teams in an area with opportunities of partnership activities with Indian institutions and of potential interest for industrial companies. We intend also identify research guidelines focused to the bilateral cooperation to apply for EU funding and setup new bilateral scientific and technology agreements for strategic researches.

Scientific coordinators
Augusto Marcelli
INFN-LNF Frascati

Balasubramanian Chidambara
Institute for Plasma Research Gandhinagar

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