MRI: Acquisition of a Cryogenic, Aberration-Corrected Scanning Transmission Electron Microscope for Advanced Materials Research and Education

Cornell University, Ithaca NY

Investigators

Abstract

Nontechnical: This award supports the acquisition of a first-of-its-kind electron microscope that allows materials to be studied in their natural environment using an electron beam that can be focused down to a subatomic spot, producing three-dimensional images of their structure and chemistry. While traditional electron microscope studies are limited to only materials that can survive in a hard vacuum comparable to that of outer space, this new instrument will, for the first time, allow researchers to take snapshots of both solids and liquids, and more importantly see the processes that occur at interfaces between solids and liquids stabilized by snap freezing. Understanding such interfaces has a wide-ranging impact, from enabling scientists and engineers to design more durable batteries, more efficient catalysts for automotive fuel cells, to better retain nutrients in soil. To meet the huge demand for this capability both across campus, and also from industries and universities across the country, this instrument will be available as part of Cornell Center for Materials Research (CCMR) to researchers and students across campus as well as from other universities, industry and national labs. The microscope will also provide hands-on research opportunities for undergraduates, particularly under-represented minorities and women as part of the CCMR Research Experience for Undergraduates program, offer middle school girls the opportunity to experience the excitement of science as part of the Expanding Your Horizons program, and support K-12 teachers development through CCMR's Research Experience for Teachers program, and through MicroWorld, a microscopy-based activity that will be adapted to meet the challenges of the Next Generation Science Standards. This instrument will have broad impacts on science research and training by providing unique characterization capabilities of materials and devices and by educating a new generation of electron microscopists, which will lead to major scientific and technical advances in broad areas of research that are critical to the fulfillment of the nation?s research agenda, and the maintenance of the country's competitive position in critically important fields of science and technology. Technical: Recent advances in electron microscopy design have opened a new era of atomic resolution imaging and spectroscopy inside solids. Liquid/solid interfaces have yet to be imaged at high spatial resolution, but play a critical role in a range of biological, chemical and physical processes from catalysis to electrochemical energy storage to the formation of biominerals. With the ability to study liquids snap-frozen in a vitreous state, this cryo-STEM, combining the low-vibration cryo-stages from biology with the resolution-enhancing aberration-correctors from materials science, will enable presently unfeasible structural and spectroscopic studies of electrode/electrolyte interfaces in batteries and fuel cells, organic/mineral interfaces in breast cancer tumors and calcified aortic valves, and liquid/mineral complexes in soils. More generally, this class of "hard/soft" interfaces between minerals and liquids or soft tissue has not been explored at high spatial resolution, as the methods for studying the "hard" and "soft" components have been incompatible. Operating at cryogenic temperatures will also allow users to gain unprecedented insights into the macromolecular organization of cellular environments at nanometer resolution and to access a new range of emergent electronic states and phases in artificially engineered materials and strongly-correlated systems. With the ability to capture the early stages of nucleation at interfaces, long unanswered questions in fields across multiple disciplines from biomineralization to energy conversion and storage, complex electronic materials and carbon sequestration using soils can be addressed.