MSE Seminar Series: Electron spin resonance spectroscopy for micro-structural analysis
Speaker: Nandita Abhyankar, Assistant Research Scientist, Institute for Research in Electronics and Applied Physics (IREAP), UMD; Physical Measurement Laboratory, NIST
Title: Electron spin resonance spectroscopy for micro-structural analysis of sub-nanoliter volume samples
In this talk, Dr. Abhyankar will delineate the motivation for, and her recent work in, enabling electron paramagnetic resonance (EPR) spectroscopy of electron-spin ensembles with volumes smaller than a nanoliter. Paramagnetic centers (for example, transition metal ions and free radicals) are direct probes of atomic-scale structure and dynamics in a wide range of solid-state, polymeric, and biomacromolecular materials. Electron paramagnetic resonance (EPR) spectra of paramagnetic centers report on phase identity, motional dynamics, interstitial defect identity, and radiation dosage. Many samples with volumes in the range of nanoliters to femtoliters are currently inaccessible by EPR spectroscopy. Therefore, critical spectroscopic information is currently hidden due to a lack of sensitivity. Abhyankar's team has recently reported a new class of microresonators for EPR spectroscopy, which allow them to probe sub-nanoliter volumes of samples with micromolar concentrations. She will discuss the advantages of this design, current applications and design adaptations for future applications including EPR spectroscopies of nanoliter volumes and thin-films/interfaces.
Nandita Abhyankar is an Assistant Research Scientist at the Institute for Research in Electronics and Applied Physics, University of Maryland, College Park. She conducts research at the National Institute of Standards and Technology, Gaithersburg, MD, USA. Her doctoral work at Florida State University includes physical and spectroscopic studies of phase transitions in perovskite-like multiferroic metal-organic frameworks. Her post-doctoral work focuses on development of microresonators for EPR spectroscopy of picoliter-volume samples. As a co-PI funded by NIGMS, she is currently working to integrate microfluidics and variable-temperautre capabilities with the aforementioned microresonators.