Dr. Andy Stewart
Dr Andy Stewart is a new Lecturer (2017) in Physics and a meter of the Bernal Institute at the University of Limerick (UL). His expertise is in the fields of electron microscopy and phase retrieval techniques, specialising in electron diffraction techniques with an emphasis on solving unknown crystal structures from nano-sized crystals across a wide range of crystal types from metals, and hard matter to metal organic frameworks and Pharmaceutical crystals to protein crystals. The flexibility of electron imaging and diffraction enable us to not only ascertain the average crystal structures but also to analyse defects, interstitials, surface effects and the composition of the crystals by energy dispersive spectroscopy (EDS) and probe more deeply in the bonding, plasmonic effects and material band gap with electron energy loss spectroscopy (EELS). He is also significantly involved in managing the current electron microscopy facilities in UL’s Materials and Surface Science Institute (MSSI), and in building up the new International Centre for Ultra-High Resolution Imaging and Characterisation. He played a pivotal role in gaining an award for in situ microscopy facilities and fast, sensitive detectors which can acquire data at frame rates of up to 1600 frames per second. The combination of fast frame rates and in situ microscopy is opening many new areas for the application of electron microscopy and will place UL at the forefront of these developments. HE is also involved in efforts to develop new electron microscopy hardware to push the limits of what is possible with electron microscopy, including sample preparation equipment, and new specimen holder development.