Temperature effect on X-ray photoelectron spectra of 3d transition metal ions

Temperature effect on 2p- 3s- and 3p X-ray photoelectron spectra (XPS) of various ions of Ti, V, Cr, Mn and Fe is studied theoretically within an isolated ion approximation. It is shown that the 2p XPS of those ions are temperature dependent even at room temperature due to a very slight energy splitting between the ground-state-term total-momentum J-components which can be thermally populated. Most significant temperature effect is expected in the 2p-spectra of Ti2+(3d2), V2+(3d3), Cr2+(3d4), Mn3+(3d4), and Mn3+(3d4) ions. The temperature effect on 3p XPS is slight. No temperature effect on 3s XPS is expected.