Designing Superhard Materials

In their Perspective, [ Kaner et al. ][1] describe recent efforts to make a material that matches or exceeds the hardness of diamond. Such a material must contain highly directional, short, and strong bonds. Hardness may also be increased by introducing a nanometer-scale structure that hinders the migration of dislocations. Despite all the scientific efforts to find a material that surpasses it, diamond remains the hardest known material. And hardness is not enough: To replace diamond in practical applications, a new superhard material must also match its other properties, such as chemical inertness. [1]: http://www.sciencemag.org/cgi/content/full/308/5726/1268