ISO 15472:2010

Overview

ISO 15472:2010 - Surface chemical analysis - X-ray photoelectron spectrometers - Calibration of energy scales provides a standardized method to calibrate the binding-energy (energy) scales of X‑ray photoelectron spectroscopy (XPS) instruments. It applies to spectrometers using unmonochromated Al or Mg X‑rays or monochromated Al X‑rays and requires instruments that incorporate an ion gun for sputter cleaning. The procedure defines how to establish a calibration schedule, test linearity, correct small drifts, and quantify the expanded calibration uncertainty at a 95% confidence level.

Key topics and requirements

• Reference materials and peaks: Uses metallic Cu, Ag and Au reference foils - specifically the Cu 2p3/2, Ag 3d5/2 and Au 4f7/2 (and the Cu L VV Auger peak for some tests).
• Instrument applicability limits: Not applicable to instruments with significantly non-linear energy errors, operated at constant retardation ratios < 10, with spectrometer resolution worse than 1.5 eV, or requiring tolerance limits of ±0.03 eV or less.
• Calibration procedure outline:
  • Prepare and sputter-clean reference foils.
  • Choose spectrometer settings and measure specified peaks.
  • For initial calibration, repeat measurements (typically seven repeats) to determine the repeatability standard deviation.
  • Test scale linearity at an intermediate energy (Ag 3d or Cu L VV depending on X‑ray source).
  • Confirm uncertainty at low and high binding energies and correct for small drifts.
• Uncertainty and acceptance: Defines methods to calculate the expanded uncertainty (95%) including contributions observed in interlaboratory studies. The standard leaves the selection of a user-defined tolerance d (commonly ≥ 0.1 eV and > ~4× repeatability s) to the analyst.
• Scope limitation: Does not provide a full per-point calibration across the entire digital energy scale - manufacturers’ procedures are required for full checks.

Applications and users

• Laboratories performing surface chemical analysis and material characterization by XPS.
• QA/QC and metrology teams seeking reproducible binding-energy calibration and documented calibration uncertainty (e.g., for ISO/IEC 17025 compliance).
• Instrument technicians and service engineers implementing scheduled calibrations, drift corrections, and linearity tests.
• Researchers and industrial analysts who require accurate chemical-state identifications based on binding-energy shifts.

Related standards

• ISO 18115-1 (vocabulary for surface chemical analysis) is normative for terminology used in ISO 15472.
• Manufacturer-recommended procedures remain necessary for complete instrument validation and per-address energy checks.

Keywords: ISO 15472:2010, XPS calibration, binding-energy scale, energy calibration, X-ray photoelectron spectroscopy, Au 4f, Cu 2p, Ag 3d, calibration uncertainty, sputter cleaning.