ACS Nano http://doi.org/pb4 (2013)
Carbyne is an all-carbon linear polymer and has been predicted to have interesting mechanical properties. Under normal conditions, the most stable form is made of carbon atoms linked by alternate single and triple bonds. Boris Yakobson and colleagues at Rice University have now carried out a comprehensive theoretical study of the mechanical properties of carbyne using first-principles calculations and provide insights that could be valuable for future practical applications of the material.
Under tension, carbyne can maintain its structural integrity until a force of about 10 nN is applied, outperforming graphene, carbon nanotubes and diamond. The bandgap depends on the tensile stress applied, increasing by about 80% under a 10% strain. This extreme sensitivity should make carbyne an attractive material for opto- and electromechanical applications.
Owing to its axial symmetry, the mechanical properties of carbyne under torsion can only be defined when it is chemically modified by an end group. The bandgap then becomes a function of the torsional angle and the researchers show that at near 90° angles, carbyne becomes a magnetic semiconductor, a property that could be exploited in spintronic devices.