Correlation of calculated and measured 2p spin-orbit splitting by electron spectroscopy using monochromatic x-radiation

• Published in: Journal of electron spectroscopy and related phenomena 1974, Vol.5 (1), p.217-225
• Main Authors: Barrie, A., Drummond, I.W., Herd, Q.C.
• Format: Article
• Language: English
• ISSN: 0368-2048; 1873-2526
• DOI: 10.1016/0368-2048(74)85013-9

In the past, measurements have been made of the spin-orbit splitting (2p3/ 2 -2p1/ 2) of medium to large atomic number elements. The present work is concerned with the 2p splitting in elements of low atomic number (e.g. Si,P, S, Cl). We have measured the splitting in such elements by X-ray photoelectron spectroscopy (XPS or ESCA) with the aid of an X-ray monochromator attachment which is described. The results are in good agreement with data obtained by X-ray spectroscopic techniques, and with a theoretical prediction based on the Sommerfeld formula, with a screening constant of S = 3.40. Moreover, the modified formula holds for elements up to Z = 30 as well as for the lower atomic numbers if allowances are made for deviations in the first period of transition elements which may be accounted for by the assumption of interactions between the 2p electrons and unpaired electrons in the 3d level.