XPS peak-fitting reference
Select an element for handbook binding energies, expected chemical-state shifts, spin–orbit splitting, branching ratios, and recommended constraints when fitting XPS spectra. 94 elements in the database.
s-blockp-blockd-blockf-blockselectedColored cells with bold symbols have reference data.
Ruthenium (Ru) — Z=44
Reference binding energies, spin–orbit parameters, and recommended constraints for XPS peak fitting.
Ru 3d5/2
doublet
handbook BE 280.0 eVPrimary BE
280.0 eV
Orbit split (Δ)
4.20 eV
Peak area ratio
3 : 2 (partner : primary)
Typical σ / RSF
0.80 eV · RSF 3.05
Partner line: Ru 3d3/2 at ≈ 284.2 eV (3d5/2 + 4.20 eV).
Peak-fitting constraints
- Primary center: Start near 280.0 eV for the elemental / handbook line; refine within chemical-state windows below.
- Spin–orbit splitting: Fix 3d3/2 at Ru 3d5/2 + 4.20 eV (≈ 284.2 eV). Keep splitting fixed unless literature justifies otherwise.
- Branching / area ratio: Fix partner : primary area ≈ 3 : 2 (branching ratio 0.667). Share FWHM and Lorentzian fraction between doublet components.
- Typical width (σ): Initial half-width ≈ 0.80 eV; allow modest variation, prefer shared width across related chemical states of the same orbital.
- Relative sensitivity (RSF): Handbook RSF ≈ 3.05 (relative to F 1s = 1.0). Use for quantification, not for constraining peak shape.
- Chemical-state windows: Known states span ~280.1–283.3 eV. Assign each component to a documented state; avoid unconstrained peaks outside this range without justification.
- Background: Use Shirley (or Tougaard) under the fit window; fit peaks on background-subtracted intensity.
Chemical states / expected BE shifts
| State | BE (eV) | Δ vs handbook | Description | Reference |
|---|---|---|---|---|
| Ru metal | 280.1 | +0.1 | — | Moulder1995 |
| RuO2 | 280.7 | +0.7 | — | Sarma1980b |
| RuCl3 | 281.8 | +1.8 | — | Folkesson1973 |
| RuO3 | 282.5 | +2.5 | — | Kim1974b |
| RuO4 | 283.3 | +3.3 | — | Kim1974b |
Core-level reference: Moulder1995
Auger lines
Apparent BE for Al Kα (1486.6 eV). Kinetic energy is source-independent.
| Transition | KE (eV) | Apparent BE (eV) | σ (eV) |
|---|---|---|---|
| Ru MNN | 228.0 | 1258.6 | 3.5 |
Citations used
- [Folkesson1973] B. Folkesson, Acta Chem. Scand. 27, 287 (1973). doi:10.3891/acta.chem.scand.27-0287
- [Kim1974b] K.S. Kim, N. Winograd, J. Catal. 35, 66 (1974). doi:10.1016/0021-9517(74)90184-5
- [Moulder1995] J.F. Moulder, W.F. Stickle, P.E. Sobol, K.D. Bomben, Handbook of X-ray Photoelectron Spectroscopy, Physical Electronics, Eden Prairie, MN, 1995.
- [Sarma1980b] D.D. Sarma, C.N.R. Rao, J. Electron Spectrosc. Relat. Phenom. 20, 25 (1980). doi:10.1016/0368-2048(80)85003-1
Binding energies and chemical-state assignments are compiled from publicly available handbooks and primary literature. Contact Anibal Boscoboinik to report errors or missing attributions.