title: In situ analysis of gas composition by electron energy-loss spectroscopy for environmental transmission electron microscopy.
abstract: We have developed methods for using in situ electron energy-loss spectroscopy (EELS) to perform quantitative analysis of gas in an environmental transmission electron microscope. Inner-shell EELS was able to successfully determine the composition of gas mixtures with an accuracy of about 15% or better provided that some precautions are taken during the acquisition to account for the extended gas path lengths associated with the reaction cell. The unique valence-loss spectrum associated with many gases allowed simple methodologies to be developed to determine gas composition from the low-loss region of the spectrum from a gas mixture. The advantage of the valence loss approach is that it allows hydrogen to be detected and quantified. EELS allows real-time analysis of the volume of gas inside the reaction cell and can be performed rapidly with typical acquisition times of a few seconds or less. This in situ gas analysis can also be useful for revealing mass transport issues associated with the differential gas diffusion through the system.
authors.affiliation: School for Engineering of Matter, Transport and Energy, Arizona State University Tempe, AZ 85287-6106, USA. crozier@asu.edu
authors.forename: Peter A
authors.initials: PA
authors.lastname: Crozier
authors.forename: Santhosh
authors.initials: S
authors.lastname: Chenna