TECHNOLOGY

Critical pathways in the design of nanochemical systems

The Large Area Rapid Imaging Analytical tool (LARIAT) NEXAFS end station together with a synchrotron source and advanced data mining enables critical pathways in the design of nanochemical systems. The LARIAT is one key to unlock understanding of nanochemistry based upon directed self-assembly and novel panoscopic patterning methods; the foundation of future advanced materials applied to biology, photonics and electronics.

NEXAFS is an established synchrotron-based “near-surface” characterization method uniquely able to provide quantitative information on the nature of chemical bonding (eg., bond type, bond angle, bond length), molecular concentration and orientation of molecular systems like self-assembled monolayers (SAMS). Such information is critical to understanding the behavior of new material systems and our ability to control molecular patterns in three dimensions. To that end the synchrotron provides a high brightness tunable energy source and often polarization control of the electric light vector, expanding the range of information.

The LARIAT MKII NEXAFS spectrometer produces rapid full field chemical images using a simple elegant design and basic physics principles. Deflection optics scan the synchrotron source beam rapidly across an area up to 20X20mm while the energy is tuned across an absorption edge (eg., K or L edge). Photon energy incident on the sample at resonance with an absorption edge region stimulates a highly sensitive bond dependent yield of electrons across the surface, the essence of the NEXAFS process. With the sample immersed in a high axial magnetic field coupled with a parallel magnetic field at the imaging detector, the LARIAT detects all emitted secondary electrons in parallel while preserving the spatial relationship originating from the sample.