The structure of the X-ray photoelectron spectra of light actinide compounds

The results of the X-ray photoelectron spectroscopy (XPS) studies on the structure of the outer and inner electron shells of compounds of light actinides (Th, U, Np, Pu, Am, Cm, Bk, Cf) in the binding energy (E-b) range of 0-1250 eV are generalised. The regularities of formation of the fine structure in the XP spectra of these compounds are considered. The mechanisms of appearance of such structure are analysed, and the correlations between the fine structure parameters and actinide oxidation states., the structure of the close environment, magnetic properties, the nature of the chemical bond and secondary electron processes that accompany photoemission of electrons are discussed. Experimental evidence for effective formation of the outer (E-b = 0-15 eV) and inner valence (E-b = 15-50 eV) molecular orbitals, in particular, from the fully occupied An6p and Lns orbitals of the neighbouring actinide (An) and ligand (L) atoms in the compounds in question is presented. The use of fine spectral structure parameters, together with the electron binding energies and line intensities extends significantly the scope of application of the XPS method in structural studies.