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Development of Room Temperature Ferromagnetism in Wide-band-gap Oxide Semiconductor Nanostructures


EMSL Project ID
19803

Abstract

Tailoring the physical properties and adding new functionalities to the existing semiconductors by engineering the structure, composition and particle/grain size are among the new approaches in advancing the current applications of semiconductor materials. Preparation of these materials in the nanoscale size range is more interesting due to the increased surface-to-volume ratio which might affect the structural and most other physical properties. Transition-metal doping has been proposed to introduce magnetic functionality in conventional semiconductors. The recent discovery of ferromagnetism in transition-metal-doped oxide semiconductors such as TiO2, ZnO and SnO2 by the PI [1-8] and other research groups suggest that these are promising candidates for spintronic applications. The high Curie temperatures (up to 850 K) of these transparent semiconductors and the strong dependence of the ferromagnetic properties on dopant concentration and oxygen stoichiometry make them attractive materials for magnetic/spintronic device applications and for novel magnetic gas-sensing [9-10]. These technological applications require that Sn1-xMxO2 be prepared with superior properties in the form of nanoparticles and thin films. Since ferromagnetism in transition metal doped semiconductors could also result from dopant clusters and other impurity phased, thorough characterization of the materials to confirm the intrinsic origin of ferromagnetism is extremely important.

Project Details

Project type
Large-Scale EMSL Research
Start Date
2006-08-01
End Date
2009-09-30
Status
Closed

Team

Principal Investigator

Alex Punnoose
Institution
Boise State University

Team Members

Aaron Thurber
Institution
Boise State University

Related Publications

Johnson L, AP Thurber, J Anghel, M Sabetian, MH Engelhard, D Tenne, C Hanna, and A Punnoose. 2010. "Transition Metal Dopants Essential for Producing Ferromagnetism in Metal Oxide Nanoparticles." Physical Review. B, Condensed Matter 82(5):Art. No. 054419. doi:10.1103/PhysRevB.82.054419
Wang H, D Wingett, MH Engelhard, K Feris, KM Reddy, P Turner, J Layne, C Hanley, J Bell, D Tenne, CM Wang, and A Punnoose. 2009. "Fluorescent Dye Encapsulated ZnO Particles with Cell-specific Toxicity for Potential use in Biomedical Applications." Journal of Materials Science. Materials in Medicine 20(1):11-22.