Electron inelastic mean free path in water

Murat Nulati Yesibolati, Simone Lagana, Shima Kadkhodazadeh, Esben Kirk Mikkelsen, Hongyu Sun, Takeshi Kasama, Ole Hansen, Nestor J. Zaluzec, Kristian Mølhave*

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Liquid phase transmission electron microscopy (LPTEM) is rapidly developing as a powerful tool for probing processes in liquid environments with close to atomic resolution. Knowledge of the water thickness is needed for reliable interpretation and modelling of analytical studies in LPTEM, and is particularly essential when using thin liquid layers, required for achieving the highest spatial resolutions. The log-ratio method in electron energy-loss spectroscopy (EELS) is often applied in TEM to quantify the sample thickness, which is measured relative to the inelastic mean free path (λIMFP). However, λIMFP itself is dependent on sample material, the electron energy, and the convergence and divergence angles of the microscope electronoptics. Here, we present a detailed quantitative analysis of the λIMFP of water as functions of the EELS collection angle (β) at 120 keV and 300 keV in a novel nanochannel liquid cell. We observe good agreement with earlier studies conducted on ice, but find that the most widely used theoretical models significantly underestimate λIMFP of water. We determine an adjusted average energy-loss term Em, water, and characteristic scattering angle θE, water that improve the accuracy. The results provide a comprehensive knowledge of the λIMFP of water (or ice) for reliable interpretation and quantification of observations in LPTEM and cryo-TEM studies.
Original languageEnglish
JournalNanoscale
Volume12
Pages (from-to)20649-20657
ISSN2040-3364
DOIs
Publication statusPublished - 2020

Fingerprint Dive into the research topics of 'Electron inelastic mean free path in water'. Together they form a unique fingerprint.

Cite this