Spintronics & Multiferroics

Spintronic Device Materials: Stringently controlled experimentation on nanorods of ZnO doped by Li has resulted in room temperature ferromagnetism. A comprehensive theory has been formulated based on a correlated model for oxygen orbital with random potentials introduced by Li atoms which ultimately induced local magnetic moments on oxygen atoms. Physical Review B, Vol. 79, 12, 2009.

Spin Hall Effect: Spin waves generated by resonance in conducting ferromagnetic layer experience scattering, which causes less spin diffusion length. Microwave induced spin-Hall effect of Co/Pt bilayer thin film showed maximum dc voltage of 5.78 µV at 0.1 GHz.

Nano-magnetism: Multifunctional Ferromagnetic Carbon nanotube arrays has been manipulated for mechanical motion by pulse- injection CVD. MWCNTs biological compatibility, higher delivery efficiency with a prolonged release of cancer drug doxorubicin (Dox), and good targeting capabilities of Dox onto HeLa cells have been demonstrated. For the first time ferromagnetic three-dimensional free standing pillar architecture of multiwall carbon Nano-tubes has been synthesized and experimentally supported to act as Nano mechanical rotor & drug delivery carrier. AngewandteChemie-International Edition 51 (2012): 2916-2919.

Magneto-electric Coupling in Multiferroics: Room temperature Magneto electric coupling enhancement in new materials & composites are being developed. Magnetic, dielectric and calorimetric Studies on 0.9BiFeO3-0.1BaTiOindicate strong magneto electric coupling. The results obtained confirm first atomic level evidence for magneto-electric coupling of intrinsic multiferroic origin in a bismuth ferrite based system. Dynamic magneto electric capacitance has been tuned in a strategically RF deposited BiFeO3 layer sandwiched between BaTiO3. The maximum longitudinal MEC (αME) of ~ 515 mV/cm.Oe was observed in tri-layer film. Physical Review Letters, Vol. 101, 24, 2008.