Volume 7 Issue 9, September 2008

Nuclear energy offers a low-carbon footprint and less dependence on fossil fuel, but several materials challenges must be met to advance nuclear technology.

As interest in new generations of nuclear reactors is increasing worldwide, renewed research effort into new materials more tolerant to extreme conditions is crucial.

The present revival in nuclear technology is prompting concerns about its safe use. Nature Materials talks to Tomihiro Taniguchi, Deputy Director General at the International Atomic Energy Agency, responsible for nuclear safety and security.

The synthesis of chiral magnetic molecules allows the first observation of strong magneto–chiral dichroism, where unpolarized light is absorbed differently for parallel and antiparallel propagation with respect to an applied magnetic field.

Multiscale experimental and computational approaches reveal how an ancient fish protects itself with an armour of scales consisting of four different reinforcing, graded nanocomposite layers.

Oxide materials have long been known as hosts for exotic and useful physical properties. Recent advances in their design and fabrication establish the means to tailor their response for applications.

We are used to thinking that a macroscopic phenomenon can be described in terms of either classical physics or quantum mechanics. But sometimes it can be both. For example, it is shown that the linear magnetoresistance in InSb can be achieved by a classical or quantum route.

Nanowire lasers have so far consisted of homogeneous semiconductor structures. The achievement of lasing from a multi-quantum-well heterostructure deposited on a nanowire demonstrates a new complexity in nanophotonic devices.

Geometric information on lithium diffusion is crucial to understanding electrode reactions for lithium ion battery applications. Combining high-temperature powder neutron diffraction and the maximum entropy method, experimental evidence for a curved one-dimensional chain for lithium motion in Li_xFePO₄ is now provided.

Pores in thin films tend to lie in the plane of the substrate, which makes it impractical for applications where diffusion into the pores is necessary. Nanometre-scale epitaxy on a patterned substrate is now used to form vertically oriented pores in honeycomb-structured films.

Precise control over the geometry of nanoscale one-dimensional structures is challenging. Cylindrical polymer brushes have now been used to synthesize organo-silica hybrid nanowires that are not only soluble in water but also in many organic solvents.

The observation of Rabi-oscillations between single and triplet states in an organic light-emitting diode demonstrates the possibility of manipulating the spin states in organic electronic devices. The data also provide direct evidence of very slow spin-dephasing, which should prove crucial for the development of organic spintronics.

Magneto-chiral dichroism is an effect in which unpolarized light is absorbed differently for parallel and antiparallel propagation with respect to an applied magnetic field. Previous observations have only seen a rather weak demonstration of this effect. Following a challenging synthesis, strong magneto-dichroism has now been observed in enantiopure chiral ferromagnets.

In solid-state lighting, phosphors are typically used to complement the blue light of the original emitter to achieve white-light emission. The capability to deposit certain phosphors at much lower temperatures than previously enables their use on organic substrates and opens the door to fabricate large-area white-light emitters.

Electrodes exhibiting single-phase lithium insertion processes can be advantageous for storage applications such as lithium-ion batteries. By modifying the particle size and ion ordering of LiFeFO₄ electrodes an unprecedented single-phase room-temperature process is observed.

The scales of a fish are its first level of defence. Now, the multilayered structure of fish scales has been analysed according to its mechanical properties and penetration resistance. This study of the four different layers provides a mechanistic understanding of evolutionary design as well as inspiring new materials for armour protection.

The steep rise in fossil fuel prices has triggered a revival of interest in nuclear energy. This focus takes a look at where we stand with nuclear technology, and what materials research is needed to realize next-generation nuclear reactors.