{'fraction_non_alphanumeric': 0.01905311778290993, 'fraction_numerical': 0.004618937644341801, 'mean_word_length': 5.614503816793893, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 1, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Probing Properties of Nanomaterials with Advanced Electron Energy-Loss Spectroscopy

Electron energy-loss spectroscopy (EELS) is a powerful tool for characterizing the composition and properties of materials at the nanometer level. Developments over the last 10 years in the areas of monochromators, spectrometers, and electron detectors now make it possible to probe excitations in solids from the meV to keV range, with atomic resolution possible in many cases. The types of excitations that can be probed with EELS includes phonons, polaritons, plasmons, excitons, photonic modes, interband and bandgap transitions, as well as inner-shell transitions to states above the Fermi level. This potentially provides a huge amount of local information about vibrational, electronic, optical, and magnetic properties of the materials. Many of these signals can also be acquired from samples under in situ or operando conditions, providing critical links between dynamic changes in materials properties and functionalities Current detector technology can reach readout rates in excess of 3,000 spectra per second, enabling both high spatial and temporal resolution to be achieved. Emerging data science techniques such as machine learning will play a critical role in extracting information from very large spectral datasets. At Arizona State University, our advanced EELS capability is primarily focused on two machines. The Nion UltaSTEM provides an energy resolution of about 6 meV, enabling phononic, photonic, and bandgap states to be probed with atomic resolution. We recently installed a Gatan Image Filter with a direct electron K3 camera on our FEI Titan environmental transmission electron microscope, dramatically improving our