Issue Date: April 23, 2007
Rhenium diboride stands up to diamond
With its milquetoast metallic appearance, rhenium diboride (ReB2) probably won't usurp the place of diamond as a girl's best friend. But the superhard material could replace diamond in certain industrial applications, thanks to its ultra-incompressible nature and its relatively simple synthesis. Sarah H. Tolbert, Richard B. Kaner, and coworkers at UCLA prepared the metallic form of ReB2 in bulk quantities under ambient pressure via an arc-melting procedure (Science 2007, 316, 436). The material's average measured hardness is comparable to that of other superhard materials, such as cubic BN or B6O, which must be made at extreme pressures and temperatures. It falls short of being as hard as diamond, but Tolbert and Kaner believe their measurement represents only a lower limit of ReB2's hardness. Rhenium diboride can scratch the surface of natural diamond, however, indicating that it's one of the hardest materials known.
- Chemical & Engineering News
- ISSN 0009-2347
- Copyright © American Chemical Society