Nature Nanotechnology - Current issue : November 2008 - Vol 3 No 11
- Self–assembled superlattices
- Nanophotonics: Waveguides and nanowires get connected
- Sensors: Extra leverage against superbugs FREE
- Nanobiotechnology: Designing artificial cells
Latest highlights
Advance online publication
Semiconductor nanowires
Article by Caroff et al.The growth temperature and diameter of indium arsenide nanowires have been tuned to fabricate highly–reproducible polytypic and twin–plane superlattices within single nanowires. In addition to reducing defect densities, this level of control should also lead to band–gap engineering and novel electronic behaviour.
Advance online publication
When a spin–polarized current passes from a ferromagnet into a non–magnetic material, the spins of the itinerant electrons are 'flipped' at the interface between the two materials, producing a mechanical torque. A nanoscale torsion oscillator has now measured this torque in a metallic nanowire in which one half is ferromagnetic and the other is non–magnetic.
Advance online publication
Assembly and imaging
Letter by Kufer et al.The mechanical deposition of single molecules on a surface can be optically monitored with nanometre precision using a combination of total internal reflection fluorescence microscopy and atomic force microscopy.
Advance online publication
Negative thermal expansion
Letter by Zheng et al.Most solids expand when they are heated, but some non–magnetic materials expand when they are cooled. Researchers have now observed evidence for negative thermal expansion (NTE) in nanocrystals of two magnetic materials. Moreover, the NTE effect in nanocrystals of CuO is four times larger than that observed in the celebrated NTE material zirconium tungstate.
Research Highlights
Harnessing optical forces on a silicon chip, nanocrystals with almost universal solubility, and manipulating individual molecules without touching them.
Advance online publication
Quantum dots
Letter by Clifford et al.Previous photodetectors based on solution–processed colloidal quantum dots have demonstrated either rapid response times or high sensitivity. Researchers have now taken advantage of new insights into charge transport in these devices to build photodiodes that offer both rapid response times and high sensitivity.