Volume 7 Issue 5, May 2008

New dosimeters are needed to measure radiation up to extreme levels created by particle accelerators and nuclear fusion reactors. The time to develop these dosimeters is now.

Sea cucumber skin is the architectural basis for polymer nanocomposites that can adapt their mechanical properties in response to biomedically relevant chemical stimuli, in a similar fashion to the animals' self-defence mechanism.

The interplay of various mechanical forces leads to characteristic shapes of torn adhesive films. Analysis of these shapes provides potential for new approaches to material characterization.

The successful synthesis of highly crystalline Cs₃C₆₀, exhibiting superconductivity up to a record temperature for fullerides of 38 K, demonstrates a powerful synthetic route for investigating the origin of superconductivity in this class of materials.

The systematic development of phase-change materials has been hampered by experimental and computational difficulties. The first successful modelling of the full phase-change cycle therefore closes an important gap.

A chemically driven process turns the classic insulator, gallium oxide, into a metal by the formation of a heterogeneous mixture of crystalline and amorphous regions.

The combination of high-mobility charge transport and efficient luminescence in one material has so far proved elusive in semiconducting polymers. Varying the side groups on a single polymer can improve both properties simultaneously.

C₆₀-based solids are the archetypal molecular superconductors, reaching transition temperatures as high as 33 K. Now, Cs₃C₆₀ solids, having a transition temperature of 38 K, have been isolated. Both face-centred-cubic and body-centred-cubic phases were synthesized, and, uniquely among C₆₀ solids, the superconducting phase was found to be body-centred cubic.

Despite the demonstration that nanowires can grow below the eutectic point, a clear understanding of how this happens has not been reached. Video-rate transmission electron microscopy brings new insight into the issue, showing in real time the growth of silicon nanowires with palladium catalysts.

Efficient light emission combined with high charge-carrier mobility has proven elusive for polymer semiconductors, because high mobility is typically achieved using approaches that quench luminescence. A new strategy, introducing a limited number of more-effective hopping sites between otherwise relatively isolated polymer chains, achieves this aim.

Microporous materials such as zeolites are widely used in separation and catalytic applications. A thermally stable family of zeolites with chiral and achiral structures built from the same layer is now reported.

We’re all familiar with the annoying problem of trying to peel sticky tape from a surface, only for the detached piece to narrow into a point and break off. Surprisingly, this phenomenon can be put to good use in deriving the mechanical parameters of a wide variety of thin, adhesive films.

Inducing and understanding insulator–metal transitions in binary oxide can be challenging. A transition driven chemically by an internal redox reaction is now observed in a non-stoichiometric, amorphous gallium oxide.

Phase-change materials are of commercial interest for their use in rewritable optical disks and as non-volatile memories, although little is known about the dynamics of the phase transition. The numerical simulation of the entire write-erase cycle therefore provides important clues towards the development of new phase-change materials.

The large-scale production of high-quality graphene layers is one of the main challenges to be overcome for successful application of this material. Epitaxial growth on ruthenium substrate produces homogeneous domains of single- and double-layer graphene on the scale of several tens of micrometres. The electronic properties of the second layer show great potential for applications.

Chiral detection using organic sensors has been limited to concentration levels of parts-per-thousand. The use of a thin-film transistor and of semiconducting oligomers with chiral side arms improves differential detection of enantiomers to parts per million.