Scattering and Instrumentation Sciences
Scattering and Instrumentation Sciences
This program area encompasses basic research in condensed matter physics and materials physics using electron, neutron, and x-ray scattering capabilities. Research includes experiment and theory that seeks to achieve a fundamental understanding of the atomic, electronic, and magnetic structures and excitations of materials as well as the relationship of these structures and excitations to the physical properties of materials. Also supported is the study of fundamental dynamics in complex materials, correlated electron systems, nanostructures, and novel systems using advanced ultrafast spectroscopy, diffraction and microscopy. The emphasis is on using time-domain approaches to provide new understanding of complex behavior, emergent phenomena, and exotic properties in condensed matter. Another increasingly important aspect is the study of the nature of materials at the nanoscale including ordering fluctuations, and the structure and composition of inhomogeneities such as defects, interfaces, surfaces, and precipitates.
Advancing the state of the art of electron beam and scanning probe techniques and instrumentation for quantitative microscopy and microanalysis is an essential element in this portfolio. The increasing complexity of energy-relevant materials such as superconductors, semiconductors, and magnets requires continuing development and improvement of next-generation x-ray and neutron scattering instrumentation for characterizing the atomic, electronic, and magnetic structures of these materials. This includes a full range of elastic, inelastic, and imaging techniques as well as ancillary technologies such as novel detectors, sample environment, data analysis, and technology for producing polarized neutrons.
Program Leader: Nitash Balsara
Co-PI's: Ken Downing, Christian Kisielowski, Jeffrey Kortright, Andrew Minor, Ronald Zuckermann
We will study charge transport in polymer membranes by electron scattering and microscopy. We focus on self-assembled nanostructures formed by bio-inspired peptoids and synthetic block copolymers within which ion transport is restricted to one of the nanostructures. We aim to determine the geometry and chain configurations that lead to the most efficient solid-phase ion-transporting channel. Spatially resolved electron microscopy and energy-loss spectroscopy are crucial for obtaining the relationship between morphology and transport. Our microscopy techniques focus on maximizing spatial and energy resolution while minimizing radiation exposure and damage. We will manipulate and detect the incident, transmitted, and scattered electrons using aberration-correctors, high brightness instruments, and novel 3D image reconstruction algorithms. In-situ electron microscopy experiments to investigate the dynamic nature of soft materials on molecular and sub-molecular length scales have been designed. This project will investigate if the resolution in soft materials of interest can be extended to sub-nanometer length scales. We will develop materials with unique properties, e.g. membranes that become wetter when they are heated in air and mechanically robust solid electrolytes for battery applications.top
Program Leader: Robert Schoenlein
Co-PI's: Robert Kaindl, Joseph Orenstein
This program applies advanced ultrafast techniques to fundamental problems in condensed matter physics. The focus is on: complex materials where correlation among charges and between charge, spin, and phonons lead to new properties, quasiparticles, and exotic phases; and novel physics at interfaces and in nanostructured materials. Ultrafast spectroscopy provides new insight by separating correlated phenomena in the time domain with resolution shorter than the underlying coupling processes. The program consists of four coupled research areas: (1) understanding charge, spin and quasiparticle dynamics via THz spectroscopy and time-resolved four-wave mixing, (2) understanding magnetization dynamics via transient spin grating and magneto-optic Kerr spectroscopy, (3) understanding cooperative phase transitions, critical phenomena, and electron phonon coupling via ultrafast visible and mid-IR spectroscopy, and (4) understanding atomic and valence‑electronic structural dynamics in complex materials via ultrafast VUV/EUV angle-resolved photoemission and X-ray spectroscopy. Measurements of correlated phenomena on fundamental time scales, at atomic spatial scales, with momentum resolution and element specificity are indispensable for achieving new insight onto the emergent physics of complex materials and nanostructures.top