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Workshop / Seminar

CHE 598 seminar by Dr. Daniel Perea

Center for Undergraduate Education (CUE)
CUE 114 - Pullman Campus Floyd 256 - Tri-Cities Campus

About the event

“Enabling New Science with Atom Probe Tomography via Environmentally Protected Specimen Handling” presented by: Dr. Daniel Perea

BIOGRAPHY:

Dr. Perea is a senior staff scientist at the Environmental Molecular Sciences Laboratory at the Pacific Northwest National

Laboratory. He received his Ph.D. in Materials Science & Engineering from Northwestern University in 2009, where he established

the application of APT to directly map dopant impurity incorporation in low-dimensional semiconductor nanostructures. His current

interests at PNNL include developing unique cryogenic-based and environmentally protected techniques and protocols to pioneer

the use of APT to probe the composition and structure of environmentally sensitive materials related to energy and the

environment.

 

ABSTRACT:

The liquid/solid and gas/solid interface represents a rich scientific and technological frontier for discovery and innovation in many

areas of science. However, the direct nano- to atomic-scale characterization of these interfaces is technically challenging within

broad range of analytical tools that require high to ultrahigh vacuum conditions. This challenge has been largely addressed within

the electron microscopy community through the development of unique specimen holders and differentially-pumped vacuum

systems that allow researchers to probe, in situ, liquid/solid and gas/solid interfaces using electron probes. However, the direct

application of APT to liquid/solid and gas/solid interfaces is not possible and requires the development of unique specimen

preparation and handling of cryogenically-frozen specimens and/or work with specimens under environmentally-protected

conditions enabling controlled gas exposures. At PNNL, we have developed a unique suite of hardware and experimental

protocols for the preparation, handling, and analysis of environmentally-sensitive materials centered around a unique

environmental transfer hub, in situ environmental chemical reactor, specimen suitcase device, and modified cryo FIB/SEM

capabilities. The ability to prepare, manipulate, and transfer specimens under either cryogenic or vacuum conditions thus provides

a means to uniquely apply APT analysis to a wide variety of material systems that would not be possible otherwise. Here I will

describe some new science areas relevant to structural biology and catalysis that can be explored with APT analysis applied to

temperature sensitive material systems requiring cryo specimen preparation and transfer, as well as air sensitive material systems

requiring vacuum or inert vacuum transfer following controlled gas exposures.

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