This project 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 strong atomic bonds between wires. A combination of predictive computational techniques, chemical preparation, and physical characterization will be employed to identify a spectrum of scientifically and technologically important properties of these materials with a focus on electrical transport properties, mechanical response and stability, and phase transformations. This project aims to leverage a spectrum of data mining, machine learning, and materials property calculation techniques to accelerate the identification of the most promising subset of these 400 materials for synthesis and testing. The PIs will train the next generation of scientists and engineers by providing interdisciplinary research opportunities for undergraduate and graduate students with attention given to attracting those from underrepresented groups. Emphasis will be placed on training with respect to computationally-led and data-drive approaches to materials research. Specifically, undergraduate students will develop Java-based software for materials science and graduate students will host a podcast aimed at disseminating developments in data-driven computational science.
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 that do not exhibit such vdW layered structure, such as copper, 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 when thinned to nanoscale cross sections, rivaling the favorable characteristics of the native bulk form of copper, with potential applications in the miniaturization of electronic devices. Another hypothesis is that these materials may be more likely to exhibit electronic or structural phase changes that can be engineered for low power electronic memories and other applications.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
