Synthesis and characterization of highly monodisperse transition metal-doped ZnO nanocrystals

CHED 24

O. Perales-Perez, oscar@ge.uprm.edu1, Adrian Parra, adriagi@yahoo.com2, Amaliris Ruiz, Amaliris.Ruiz@kcc.com3, Carlos Rinaldi-Ramos, crinaldi@uprm.edu3, Weiji Jia, wjia@uprm.edu2, and M. S. Tomar, mtomar@uprm.edu2. (1) Department of General Engineering-Materials Science and Engineering, University of Puerto Rico, Mayaguez, PR 00681-9000, (2) Department of Physics, University of Puerto Rico at Mayaguez, Mayaguez, PR 006890-9044, Mayaguez, PR 00680, (3) Department of Chemical Engineering, University of Puerto Rico at Mayaguez, Mayaguez, PR 00680-9044, Mayaguez, PR 00680
The recent finding of semiconductor materials with magnetic properties has attracted the attention due to its potential applications in spintronics. We present here the results on synthesis and characterization of TM-doped ZnO nanocrystals, (where TM= Co, Ni, Fe and Cu). Stable suspensions of these materials were produced in ethanol at room-temperature. XRD characterization of doped systems confirmed the complete formation of host ZnO only after aging at room-temperature. For instance, the host structure was developed after 6 days of aging when the atomic fraction of Ni was 0.02. HRTEM analyses revealed the high monodispersity of the 6-8 nm nanocrystals. The inhibition of crystal growth in presence of dopants was evidenced by the blue shift in UV-Vis absorption peaks with respect to bare ZnO. PL and UV-Vis measurements confirmed the crystal growth during aging. Doped nanocrystals were paramagnetic or weakly ferromagnetic at room temperature, in contrast with diamagnetic ZnO.
 

NSF Partnership for Research and Education in Materials
8:30 AM-11:40 AM, Sunday, 10 September 2006 San Francisco Marriott -- Salon 11, Oral

Division of Chemical Education

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006