Abhijit P. Jadhav

Red emitting Y2O3:Eu3+ nanophosphors with >80% down conversion efficiency

Obtaining nanophosphors of a controlled size and shape with a high quantum efficiency is the current challenge for display and imaging technologies. Although the surface state induced luminescence quenching in nanophosphors may be compensated to some extent by incorporating activators like rare-earth ions, or by exploiting their quantum size effect, obtaining nanophosphors with quantum efficiencies as high as their bulk counterparts remains elusive. In the present article, we report on the synthesis of uniform Eu-doped Y2O3 nanoparticles, with an average size of 20–53 nm and a down conversion efficiency as high as 85%, using a simple chemical precipitation technique. Along with size control, the effects of Eu3+ content on their emission behaviors have been discussed. We believe the low-cost synthesis process of these nanoparticles will greatly enhance their application potential in optical display and bio-imaging technologies.

One pot synthesis of hard phase Nd2Fe14B nanoparticles and Nd2Fe14B/α-Fe nanocomposite magnetic materials

Nanophase materials with an average grain size in the range of 1 to 50 nm have attracted research interest for more than a decade since their physical properties are quite different from that of their bulk micron-sized counterparts. The properties of magnetic materials are highly dependent on its particle size. The synthesis of hard phase magnetic nanoparticles was carried out in a one pot reaction. By controlling the reaction conditions, the exchange coupling between the hard and soft phase in the hard/soft nanocomposite magnetic material has been studied. The reaction parameters, such as the ratio of the metallic precursors, reaction temperature and reduction process, play an important role in determining the shape and size of the material along with its magnetic properties. To produce the exchange coupling between hard and soft phases their particle size needs to be controlled very precisely, which can help to increase the interaction between the two phases. By controlling the ratio of precursors, the amount of soft phase of α-Fe was optimized for the synthesis in situ with the hard phase Nd2Fe14B material.