Overview
ISO/TR 18394:2016 is a Technical Report from ISO/TC 201 (Surface chemical analysis) that provides guidelines for identification and use of chemical (solid‑state) effects in X‑ray‑ or electron‑excited Auger‑electron spectra. The report explains how Auger‑electron spectroscopy (AES) can be used not just for elemental surface analysis but also for deriving chemical-state information - e.g., oxidation states, bonding environment and local electronic screening - using shifts, line shapes and satellite structure in Auger spectra.
Key topics
- Types of chemical and solid‑state effects observed in Auger spectra (energy shifts, line‑shape changes, satellites, inelastic-loss structure).
- Core‑level (CCC) Auger transitions: identification and interpretation of chemical shifts of Auger‑electron energies.
- Auger parameters and the modified Auger parameter (α′): how kinetic‑energy separations between Auger and photoelectron peaks provide chemical‑state diagnostics and are largely insensitive to charging.
- Chemical‑state plots, databases and recommended reference Auger energies (coverage noted for multiple elemental solids).
- Chemical effects on satellite features, relative intensities and CCC/CCV/CVV line shapes.
- Valence‑involved Auger transitions (CCV, CVV): sensitivity to local electronic structure and bonding.
- Practical measurement considerations: use of direct vs differentiated spectra, required relative energy resolution (better than ~0.15%, with examples of 0.05% or 0.02% for fine chemical‑state work), and caution about energy referencing (Fermi vs vacuum level differences on the order of ~4–5 eV).
Applications
ISO/TR 18394:2016 guides practitioners who need to extract chemical information from AES data, including:
- Identification of surface chemical species and oxidation states in corrosion, catalysis and thin films.
- Chemical‑state mapping of nanostructures and semiconductor doping (high‑resolution Si KLL examples are discussed).
- Characterization of insulators and semiconductors where Auger parameters help avoid charging artifacts.
- Research and development in materials science, surface engineering, and analytical laboratories using Auger electron spectroscopy and XPS/AES workflows.
Who should use this standard
- Surface analysts and spectroscopists
- Materials scientists and engineers (semiconductors, coatings, catalysts)
- Analytical laboratory managers and quality teams implementing surface chemical analysis
- Researchers developing AES data interpretation and modeling methods
Related standards
- ISO 18115 (all parts) - vocabulary for surface chemical analysis (normatively referenced in ISO/TR 18394:2016)
Keywords: ISO/TR 18394:2016, Auger electron spectroscopy, surface chemical analysis, Auger chemical shifts, Auger parameter, chemical‑state mapping, X‑ray‑excited Auger, electron‑excited Auger.
Open preview (PDF)Surface chemical analysis — Auger electron spectroscopy — Derivation of chemical information
