March 28, 2013

Even graphene has weak spots

Rice, Tsinghua theorists find junctions in polycrystalline graphene sap strength of super material

Graphene, the single-atom-thick form of carbon, has become famous for its extraordinary strength. But less-than-perfect sheets of the material show unexpected weakness, according to researchers at Rice University in Houston and Tsinghua University in Beijing.

The kryptonite to this Superman of materials is in the form of a seven-atom ring that inevitably occurs at the junctions of grain boundaries in graphene, where the regular array of hexagonal units is interrupted. At these points, under tension, polycrystalline graphene has about half the strength of pristine samples of the material.