XPS: Energy calibration of electron spectrometers. 1—An absolute, traceable energy calibration and the provision of atomic reference line energies

TLDR

Atomic binding‑energy standards are provided to calibrate X‑ray photoelectron spectrometers. Using a VG Scientific ESCA 3 Mk II, the authors measured binding energies with 5 meV precision, set the voltage scale to 11 ppm accuracy over 0–1250 eV traceable to NPL standards, defined the energy zero to ±11 meV via the Ni Fermi edge with Mg Kα radiation, and established absolute binding energies for Cu, Ag, and Au peaks with 0.01–0.02 eV uncertainty, while also evaluating literature calibrations for zero‑setting and scaling errors. Preliminary tests indicate the calibrations can be reproduced on external instruments with a simple procedure.

Abstract

Abstract Atomic standards of binding energies are presented for the calibration of X‐ray photoelectron spectrometers. The binding energies are measured using a VG Scientific ESCA 3 Mk II for which the photoelectron peak positions can be established with a measurement precision standard deviation of 5 meV. The absolute calibration of the voltage scale is established with an accuracy of 11 ppm over the binding energy range 0–1250 eV, using a measurement chain traceable to the NPL primary voltage standards. The zero of energy is set to ±11 meV on the differential of the Ni Fermi edge using Mg Kα 12 radiation and absolute binding energies, for the Cu 2p 3/2 , Cu L 3 MM, Cu 3p, Ag 3d 5/2 , Ag M 4 NN and Au 4f 7/2 peaks, are established with errors of 0.01 to 0.02 eV. An analysis is made of literature calibrations to assess their zero setting and voltage scaling errors. Preliminary tests have been made to show that the calibrations may be reproduced on instruments outside NPL using a simple work procedure.