On the basis of the XPS handbook of Moulder, the line at 130 eV should not be from Sr and I have only a vague idea of its origin. Can you rule out a phosphorous contamination? It might also be a satellite of the Sr 3d lines with an additional loss. The high width of the line at 134 eV would be inline with such a loss also on the second line of the Sr 3d line, but does not rule out other explanations. My knowledge of XPS spectra of superconductors is too limited. A careful literature inspection might reveal more about the existence of such a loss. My own brief and incomplete review of XPS from high-Tc superconductors confirms that the lines at 132 eV and 134 eV fit to Sr 3d 5/2 and 3/2 and the lines at 137 eV and 142 eV fit to Pb 4f 7/2 and 5/2. The line at 130 eV appears to be too narrow for an Auger emission line. But without knowing the excitation energy (Mg Ka or Al Ka) this check cannot be done in more details.

I assume, a check with XRD has been done whether the formation of BPSCCO is complete and no starting material is left?

Although your binding energy scale looks correct, you should always mention, how it has been referenced. C1s, Au4f, ... ?

Dear Karl-Michael Schindler

Thank you for your suggestions. It might be a satellite peak of Sr 3d but I could not find any reference to support this claim. I have checked my XRD and there are two phases Bi2212 and Bi 2223 coexist with the major volume fraction of the Bi-2223 system and to prepare this, we have not used the Phosphorous element.

In order to support your claim of a satellite, you could try a fit with two satellite lines with the same binding energy difference and intensity ratio as the "regular" Sr 3d lines. An additional satellite line to the one at 133.6 eV would explain the somewhat high intensity of the 132.3 eV line compared to the 133.6 eV line. The width of the 133.6 eV line is large in line with a bad representation of the small dip at 133. This indicates that there is something else, which is large enough to "disturb" the fit, but too small to fit with something reasonable. The small feature at 135.5 eV also increases the width of the 133.6 line. This might be a hint to a similar, but weaker feature on the Pb lines. The shape of the Pb lines also looks quite "triangular" and not like Gaussian, which hints to more features, although not obvious enough to be determined in detail. I am also wondering a bit about the inelastic background. Has it been subtracted, like with a Shirley-type background? In order to nail down the general and the inelastic background better, a wider range of the spectrum would help. Admittedly, it wouldn't answer your primary question about the satellite.