The collaborative project between UC Riverside and Stanford explores a recently discovered class of more than 400 materials that form one-dimensional wires of bonded atoms surrounded by a tubular, two-dimensional van der Waals gap avoiding any unsaturated atoms at the wire surface. A combination of predictive computational techniques, chemical preparation, and physical characterization seeks to identify a spectrum of scientifically interesting and technologically relevant properties of these materials with a focus on electrical transport properties, mechanical response and stability, and phase transformations. Bulk crystals of graphite and other materials composed of 2-dimensional van der Waals (vdW) layers exhibit numerous important properties in the bulk that are preserved as the material is thinned to atomic thickness, e.g. the high electrical conductivity of graphene. This distinguishes them from native bulk materials, such as silicon, whose properties change dramatically as it is thinned below a few atomic layers. Unlike 2D layered materials, the 1-dimensional vdW materials of this project have received relatively little research attention, but are likely to exhibit many of the useful properties of their 2D counterparts. One hypothesis is that the presence of vdW gaps and the absence of dangling bonds and large single crystal domains inhibits carrier scattering at the surface of such materials and, thus, allows for electronic transport at a resistivity almost independent of wire cross section. Recent synthesis work by the project participants has revealed excellent transport properties of such materials that can rival copper when thinned to bundles of nanoscale cross sections.
