Volume 8 Issue 10, October 2009

Cation binding is shown to trigger mesoscale domain formation within assembled mixtures of neutral and anionic polymer amphiphiles. The spotted and striped particles could be used for drug delivery or biomedical sensing.

Electron relaxation time in semiconductor quantum dots, for terahertz transition energies, can be slowed down to the nanosecond range — a very encouraging result for the development of quantum-dot-based quantum cascade lasers.

Secondary electron imaging in electron microscopy can achieve resolutions that compete with transmission electron microscopy, and allows imaging of both surface and bulk atoms simultaneously.

For more than 50 years, the International Conference on Magnetism series has been inspiring researchers in the field. At the latest meeting in Karlsruhe, Germany, the control exerted by nanostructured devices over magnetic properties was the centre of attention.

Control of the formation of nanostructures during their synthesis can be achieved using either equilibrium conditions, such as in nanostructure templating, or non-equilibrium conditions, such as in reaction–diffusion systems. This review analyses the different method types with the aim of producing guidelines for the rational design of hybrid organic–inorganic nanostructures.

High pressures have been very useful in stabilizing materials that cannot form at low pressure. However, often high-pressure phases are not stable when recovered in ambient conditions. Bombardment with high-energy heavy ions is now shown to stabilize a high-pressure phase of Gd₂Zr₂O₇ in ambient conditions.

In conventional metals, strong interactions between electrons and the atomic lattice, so-called polarons, often render metals electrically insulating. In the rare case of polaronic metals, however, polaronic properties survive even in the metallic state. Neutron-scattering experiments now reveal that it is through quantum fluctuations that polarons manifest their presence in these enigmatic materials.

Quantum cascade lasers are only one of several applications that could take advantage of the discrete nature of the energy levels in semiconductor quantum dots. It is now shown that the relaxation time between levels is highly sensitive to their energy separation. This knowledge will be essential for the design and optimization of actual devices.

A new type of scanning electron microscope with aberration correction allows a resolution of 0.1 nm. The instrument also allows for simultaneous imaging of atoms on the surface and in the bulk of a sample, which represents a real breakthrough in the field.

Controlling the magnetic properties by using an electric field is a promising route towards spintronics or magnetic data storage applications. Using dicobaltocene as a test case, it is now demonstrated theoretically that an electrostatic potential can be used to control the spin states in molecules.

The performance of hybrid solar cells depends critically on the morphology of both the polymeric and the inorganic components. Electron tomography is used to resolve the morphology in three dimensions; coupling this information with three-dimensional exciton-diffusion studies enables the differentiation of charge generation and transport as performance-limiting factors.

The ability to replace surface hydrogen by multivalent atoms to form semiconductors with tailored properties is critical for microelectronic applications. The mechanistic pathway involved in the nitridation of H-terminated silicon surfaces using ammonia vapour is now explained.

Anhydrous proton-conducting materials capable of operating at high temperature are required for fuel-cell applications. Encapsulation of a proton-carrier imidazole molecule in aluminium porous coordination polymers in anhydrous conditions results in high proton conductivity above 100 ^∘C.

The interfacial energy between a macroscopic surface consisting of different materials and a liquid is independent of the surface structure. It is now shown that because of the way in which a multicomponent nanoscale surface affects the solvent–molecule arrangement, it is both the surface structure and composition that dictate the interfacial energy.

Controlled domain formation in block copolymer mixtures or lipid bilayers could lead to more highly ordered assemblies and delivery of drugs. It is now shown that mesoscale domain formation within assembled mixtures of neutral and anionic polymer amphiphiles can be induced by the divalent cations calcium and copper.