ISO 19318:2021

Overview

ISO 19318:2021 - Surface chemical analysis - X-ray photoelectron spectroscopy (XPS) - Reporting of methods used for charge control and charge correction - specifies the minimum information to report when measuring core-level binding energies of insulating specimens by XPS. The second edition (2021) updates reporting requirements and provides practical guidance on methods to minimize surface charging and to correct measured spectra so binding-energy values are accurate and reproducible.

Key Topics

• Scope and purpose: Reporting requirements to enable evaluation, reproduction and comparison of XPS binding-energy data from insulating materials.
• Calibration: Binding-energy scale calibration is required (e.g., using ISO 15472) because chemical-state determination can require uncertainties as small as 0.1 eV.
• Specimen information (Clause 7.2): report specimen form (powder, thin film, bulk), dimensions, mounting method, and any treatment prior to or during analysis (e.g., gold deposition, Ar implantation).
• Instrument and operating conditions (Clause 7.3): report instrument model, X-ray source, beam size, analyser pass energy, energy resolution (FWHM reference), geometry and lens/magnetic use.
• Charge-control methods (Clause 7.4 and Annex A): identify components used (electron flood gun, ion gun, UV irradiation, specimen heating, evaporative gold, mesh mounting, conductive adhesives) and reasons for selection (Clause 7.5).
• Effectiveness and damage assessment (Clause 7.7): document adequacy of charge control, evidence of residual or differential charging, and any specimen modification due to mitigation methods.
• Charge-correction reporting (Clause 8): describe correction approach, the value of correction energy (Δ), and how it was determined.

Applications

ISO 19318:2021 is essential for:

• Surface-chemistry and materials scientists performing XPS on insulating samples.
• Analytical labs producing reports for customers, peer-reviewed publications, and XPS databases.
• Instrument manufacturers and service providers documenting charge-neutralization systems.
• Quality assurance and interlaboratory comparisons where reproducible binding-energy values are critical.

Practical benefits include improved reproducibility of XPS results, clearer documentation for database entries, easier peer review of reported chemical shifts, and informed selection of charge-control/correction strategies for different specimen types (powder, films, bulk).

Related Standards

• ISO 15472 - Calibration of XPS binding-energy scales.
• ISO 18115-1 - Surface chemical analysis vocabulary (terms used in spectroscopy).

Keywords: ISO 19318:2021, X-ray photoelectron spectroscopy, XPS, charge control, charge correction, binding energy, surface chemical analysis, insulating specimens.