We investigated the effect of substrate-induced strain on the metal-insulator transition (MIT) in single-crystalline VO(2) nanobeams. A simple nanobeam-substrate adhesion leads to uniaxial strain along the nanobeam length because of the nanobeam's unique morphology. The strain changes the relative stability of the metal (M) and insulator (I) phases and leads to spontaneous formation of periodic, alternating M-I domain patterns during the MIT. The spatial periodicity of the M-I domains can be modified by changing the nanobeam thickness and the Young's modulus of the substrate.

We report the synthesis of single-crystalline VO2 nanowires with rectangular cross sections using a vapor transport method. These nanowires have typical diameters of 60 (+/-30) nm and lengths up to >10 mum. Electron microscopy and diffraction measurements show that the VO2 nanowires are single crystalline and exhibit a monoclinic structure. Moreover, they preferentially grow along the [100] direction and are bounded by the (01) and (011) facets. These VO2 nanowires should provide promising materials for fundamental investigations of nanoscale metal-insulator transitions.

Plasmonics is a rapidly growing field, yet imaging of the plasmonic modes in complex nanoscale architectures is extremely challenging. Here we obtain spatial maps of the localized surface plasmon modes of high-aspect-ratio silver nanorods using electron energy loss spectroscopy (EELS) and correlate to optical data and classical electrodynamics calculations from the exact same particles. EELS mapping is thus demonstrated to be an invaluable technique for elucidating complex and overlapping plasmon modes.

The use of bottom-up fabrication of nanostructures for nanotechnology inherently requires two-dimensional control of the nanostructures at a particular surface. This could in theory be achieved crystallographically with a structure whose three-dimensional unit cell has two or more--tuneable--dimensions on the nanometre scale. Here, we present what is to our knowledge the first example of a truly periodic two-dimensional nanometre-scale phase separation in any inorganic material, and demonstrate our ability to tune the unit-cell dimensions. As such, it represents great potential for the use of standard ceramic processing methods for nanotechnology. The phase separation occurs spontaneously in the homologous series of the perovskite-based Li-ion conductor, (Nd(2/3-x)Li(3x))TiO3, to give two phases whose dimensions both extend into the nanometre scale. This unique feature could lead to its application as a template for the assembly of nanostructures or molecular monolayers.