Bifunctional Magneto-Optical FePt-CdS Hybrid Nanoparticles

This paper describes preparation of binary FePt-CdS hybrid nanoparticles by spontaneous heteroepitaxial nucleation and growth of the CdS component onto FePt-seed nanoparticles in high-temperature organic solution. FePt nanoparticles with average sizes of 4 and 9 nm were used as seeds. Lattice mismatch makes complete coating of the seed particles unfavorable, resulting in peanut-like and flower-like FePt-CdS nanoparticles. The CdS photoluminescence is quenched in 9 nm FePt-CdS hybrid nanoparticles. The band edge emission is observed in 4 nm FePt-CdS nanoparticles, albeit with substantially lower intensity than in pure US nanoparticles. We suggest that the strong FePt-size dependent photoluminescence intensity results from the interplay between interface charge transfer and quantum confinement effects.