Lecture 15

Exploiting Magnetic Properties of Nanoparticles
for their Possible Applications

S. M. Yusuf

Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085, India
E-mail: smyusuf@barc.gov.in

 Nanostructured magnetic materials have immense importance both in basic and applied research as they show novel magnetic properties. We have investigated the magnetic properties of various nanostructured materials, namely, nanocrystalline γ-Fe2O3 [1], Fe3O4 [2], Fe-Al [3], CoO [4], Ni-Pt [5], and La1-xCaxMnO3 manganites [6], nanoparticles of amorphous Fe2O3 [7], nanoclusters of Co and Ni in NaY zeolites [8], diluted magnetic semiconducting Zn0.95TM0.05O (TM: Fe, Mn and Co) nanoparticles [9], Fe filled carbon nanotubes [10], molecular nanomagnet Fe[Fe(CN)6]·4H2O [11], multifunctional La(1-x)CexCrO3 nanoparticles [12], etc. TEM, ac susceptibility, dc magnetization, X-ray diffraction, neutron diffraction, polarized neutron small angle scattering and Mössbauer spectroscopy and allied techniques have been employed to investigate the structural and magnetic properties of these nanostructured materials. The dependence of magnetic properties on (i) particle size and its distribution, (ii) atomic arrangements in the core of magnetic nanoparticles, (iii) magnetocrystalline anisotropy, (iv) interparticle interactions, (v) properties of host material, etc. has been studied by using suitable models.

 In my talk, latest understanding of intertwined structural and magnetic properties in these nanostructured materials will be revealed. Various functional properties which make these nano-materials suitable for their possible applications in various devices, such as, high density magnetic data storage, thermally assisted magnetic random access memory (MRAM), thermo-magnetic switches, magnetic drug delivery, artificial heart pump support system, magnetically assisted separation of radionuclides from nuclear waste, Spintronics, etc. will be discussed.

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