Effects of thickness on the cation segregation in epitaxial (001) and (110) La2/3Ca1/3MnO3 thin films

Electron-energy-loss spectroscopy is used to map composition and electronic states in epitaxial La2/3Ca1/3MnO3 LCMO films of various thicknesses grown on SrTiO3 001 and 110 substrates. For relatively thick films 20 nm , epitaxial tensile strain in 001 films promotes a compositional La/Ca gradient across the film thickness, being the interface La rich, while the relaxed 110 films are chemically homogeneous. In contrast, much thinner 001 and 110 LCMO films display a different La/Ca distribution, being La rich at the free surface. The observed distinct thickness-dependent composition gradient behavior reflects a balance between strain-induced elastic energy minimization and kinetic effects during growth

A facile route to self-assembled Hg//MoSI nanowire networks

Nanotechnology crucially depends on new molecular-scale materials with tunable properties. In molecular electronics, building blocks have been reduced to single molecules, while connectors have largely remained at the mesoscopic scale. As a result, the behaviour of such devices is largely governed by interface effects and hence, currently, attention is focused on finding suitable molecular-scale alternatives. In this paper we discuss a new generation of one-dimensional inorganic nanostructures aimed at to replacing the mesoscopic connectors currently used in the electronics industry. We demonstrate how chemical functionalisation of nanowires consisting of molybdenum, sulphur and iodine in conjunction with very low concentrations of molecular mercury leads to one-dimensional systems which can be easily connected opening up new pathways to controlled deposition and interface formation. © 2010 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique