Title: Spin based electronics, a new era in science and technology: Role of DMS and nanocomposite materials

Abstract

We have entered in a new age of technology, where the transport of elementary particles will be driven by its spin degree of freedom. A new electronics, which is completely based on 'spin' of electron popularly known as 'Spintronics' is a subject of current research. The basic materials required for such technology is a daunting task to materials scientists. In this talk after introducing briefly the motivation of this new technology, I will highlight the research works carried out in last decade related to (i) diluted magnetic semiconductors (DMSs) a basic material for future spintronics and (ii) metal-insulator nanocompoaites a promising materials for manipulating electron's spin motion. Ion implantation has been identified as an important tool to synthesize diluted magnetic semiconductor (DMS) materials. Synthesis of transition metal implanted ZnO as a DMS material, and their ferromagnetic properties from intrinsic to extrinsic regime will be discussed. Origin of ferromagnetism (due to substitution of transition metals in ZnO) probed by a combined study of X-ray absorption (XAS), X-ray magnetic circular dichroism (XMCD), X-ray photo electron spectroscopy (XPS), X-ray diffraction (XRD) and SQUID will be highlighted. Finally, shape engineering of magnetic nanoparticles embedded in insulating matrix and trigeering exchange bias, anisotropy and quantum mechanical tunneling of electrons will be discussed. Results will explained in the framework of thermal spike model and density functional theory.