Volume 4 Issue 6, June 2005

Volume 4 Issue 6

Grain boundaries in polycrystalline ice hinder the propagation of dislocation avalanches.

Cover design by Karen Moore

Editorial

Commentary

  • Commentary |

    One of the largest controversial issues of the materials science community is the interpretation of scaling laws on material strength. In spite of the prevailing view, which considers mechanics as the real cause of such effects, here, we propose a different argument, purely based on geometry. Thus, as happened for relativity, geometry could again hold an unexpected and fundamental role.

    • Alberto Carpinteri
    •  & Nicola Pugno

Research News

News and Views

  • News & Views |

    The notion that plasticity is governed not by the steady flow of a material under an applied stress, but by the occurrence of intermittent avalanches of defects moving through the material, is gaining increasing acceptance. A new study of plastic deformation in polycrystalline materials suggests that the situation could be even more complex than once thought.

    • Peter Sammonds
  • News & Views |

    The discovery of polymorphic crystals that have different mechanical properties could prove valuable in the study of structure–property relationships.

    • Joel Bernstein
  • News & Views |

    The finding that carbon nanotube–elastomer nanocomposites can either contract or expand reversibly on exposure to light is surprising and hard to explain. But this may create a new avenue for the development of light-controlled actuators.

    • Richard Vaia
  • News & Views |

    Doping high-temperature superconductors with calcium improves their current-carrying capacity. Two microscopy studies provide insight into how this doping works.

    • Jochen Mannhart
    •  & David A. Muller
  • Materials Witness

Review

Letters

Articles

Erratum