Materials Design and Discovery at the Nanoscale
This pillar aligns well with Argonne's overall strategic interest in materials design and discovery. Geometrical confinement and physical proximity, intrinsic to nanoscale materials, can lead to emerging properties and novel functionalities. Such discoveries are a prerequisite for the exploration of innovative concepts to address some of today's technological challenges, including energy storage and conversion, information processing and storage, and data encryption.
Atomic-Level Control of Nanoscale Materials
Material synthesis capabilities based on colloidal chemistry, epitaxial growth, and self-organization are being intensively developed at CNM. These efforts target numerous challenges, including, for example, engineering of surface ligands, enabling hybrid structures with optical-magnetic multifunctionality, exploring writable nanoscale quantum states for replacing current field-effect transistors, advanced functionalization of graphene by nanolithography, and systematic examination of block copolymers as active and directing materials for future solar cell applications.
Chemical synthetic methods for directed synthesis of functionally coupled nanomaterials are being employed for developing hierarchical systems with emergent optical, magnetic, and electronic properties. Hybrid multifunctional systems consisting of conjugated semiconductor, metallic, magnetic, and bio materials are designed to achieve both efficient energy capture and subsequent redox chemistry, resulting in energy storage in the form of separated charges. The CNM also has a strong program that seeks to understand and design functionally integrated biomolecule-inorganic hybrid conjugates and their assemblies.
Scalable Nanostructures via Fabrication and Self-Assembly
The grand challenge is to create arrays of hybrid materials that exhibit collective properties as a result of the exchange interactions between the nanoparticles in the periodic architectures. Scalable, low-cost, periodic architectures of nanostructures are obtained via self-assembly and directed assembly using fabrication methods. An understanding of light absorption, carrier dynamics, energy and charge transfer, and electric and magnetic field effects in these materials will be employed to explore the use of these engineered nanostructures in practical devices such as energy conversion and storage, advanced medical therapies, and catalysis.
Science of Nanoscale Devices
Realizing the promise of nanoscience hinges on the ability to understand and ultimately control the propagation of, localization of, and interaction among the basic quanta of energy and information — spin, charge, photons, and phonons — at the nanoscale. The Center for Nanoscale Materials is in a particularly strong position to employ direct manipulation of atoms or nanoparticles to modify the properties of and control interactions between and within nanostructures. Capabilities include low-temperature ultrahigh-vacuum scanning tunneling microscopy, which enables the manipulation and assembly of structures at the atomic scale, and expertise in nano- and micro- electromechanical systems (NEMS and MEMS) that allows for the control of nanoparticle position and nanoparticle-nanoparticle spacings with subnanometer precision through electrostatic actuation.
The following scientific challenges are being addressed:
- Nanostructures built atom-by-atom for novel properties
- Manipulation of biomimetic energy transduction
- Optical interactions between nanosystems
The CNM houses an unparalleled suite of scanning probe microscopes. With the recent addition of a 5,000 sq ft high-bay area dedicated for vibration sensitive measurements at high-magnetic field and the installation of a low-temperature combined scanning tunneling and atomic force microscope with a 6 T superconducting magnet, the CNM holds truly unique capabilities to investigate the ground state properties and phase transitions of atomic scale spin structures.
Theory and modeling also play an important role in all aspects of this theme. Current efforts include first-principles electronic structure calculations to predict optimal nanoparticles for catalysis applications, large-scale molecular dynamics calculations concerning the formation and properties of nanoscale materials, and rigorous electrodynamics calculations to predict nanoscale materials with desired optical responses.