| STUDY |
CLEAR & PRESENT SUPERPARAMAGNET New approach traps nanoparticle magnets in transparent porous glass ELIZABETH K. WILSON, C&EN WEST COAST NEWS BUREAU Albert E. Stiegman has a knack for designing useful materials in the guise of pretty colored glasses. Over the years, the Florida State University (FSU) chemistry professor has fabricated porous silica gels that fluoresce on their own or that turn vibrant oranges, yellows, and greens when they're exposed to pollutants. His latest find may be the most provocative yet: a beautiful purple glass impregnated with nanoscale-sized magnets. Not only is the bulk material transparent and superparamagnetic--that is, each nanoparticle behaves like a single independent magnetic domain--but its magnetic properties can be tuned by doping it with ammonia and exposing it to light [Angew. Chem. Int. Ed., 115, 2847 (2003)]. It's a powerful collection of properties that has a number of researchers interested in the material's potential use in devices such as magnetic switches. The nanoparticles are made of cobalt-iron analogs of the complex Prussian blue: Co3[Fe(CN)6]2. Scientists have focused intensely on this class of compounds because they make promising molecular magnets. Unlike their metal and metal-oxide counterparts, molecular magnets can be designed with precisely tailored properties. |
| UPDATE | 17.06.03 |
| AUTHOR |
Joshua G. Moore 1, Eric J. Lochner 2, Chris Ramsey 1, Naresh S. Dalal, Prof. 1, A. E. Stiegman, Prof. 1 * 1The Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306, USA, Fax: (+1) 850-644-6605 2Materials Research and Technology Center (MARTECH), Florida State University, Tallahassee, FL 32306, USA |
| LITERATURE REF. |
[Angew. Chem. Int. Ed., 115, 2847 (2003)]. |
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