Sb 3d5/2 binding energy values [1].
Curve-fitted Sb 3d and overlapping O 1s XPS spectrum.
Doublet separation for Sb 3d5/2 - 3d3/2: 9.38 +/- 0.08 eV (5 Cit. [1]).
Sb 3d5/2 -3d3/2 doublet separation: 9.34 eV [2].
Sb 3p3/2: 767 eV
Sb 2p1/2: 813 eV
Sb 3s: 944 eV
Sb 4d: 33 eV
Sb 4p: 99 eV
Sb 4s: 153 eV

A) Sb 3d5/2 overlaps with the O 1s spectrum. One needs to fit and constrain the Sb 3d5/2 and Sb 3d3/2 peaks using the 3d3/2 peaks as a guide.  Remaining area in the 3d5/2 area will be due to O 1s signal (see spectrum above).

B) Sb2O3 standard samples has Sb 3d5/2 at 530.1 to 530.3 eV. Sb2O5 standard sample is at 530.9 eV [3].

C) Sb2S3 standard sample (Stibnite mineral sample) has Sb 3d5/2 peak at 529.6 eV and S 2p3/2 at 161.2 eV [3].

D) KSbO3 standard sample has Sb 3d5/2 peak at 530.7 eV and K 2p3/2 at 292.8 eV [3].

[1] C.D. Wagner, A.V. Naumkin, A. Kraut-Vass, J.W. Allison, C.J. Powell, J.R.Jr. Rumble, NIST Standard Reference Database 20, Version 3.4 (web version) (http:/ 2003.
[2] J.F. Moulder, W.F. Stickle, P.E. Sobol, K.D. Bomben, Handbook of X-ray Photoelectron Spectroscopy, Perkin-Elmer Corp., Eden Prairie, MN, 1992.
[3] M.C. Biesinger, unpublished results (2015).