ELECTRONIC AND STRUCTURAL PARAMETERS OF PHOSPHORUS–OXYGEN BONDS IN INORGANIC PHOSPHATE CRYSTALS

Wide set of experimental results on binding energy of photoelectrons emitted from P 2p, P 2s, and O 1s core levels has been observed for inorganic phosphate crystals and the parameters were compared using energy differences Δ(O 1s - P 2p) and Δ (O 1s - P 2s) as most robust characteristics. Linear dependence of the binding energy difference on mean chemical bond length L(P–O) between phosphorus and oxygen atoms has been found. The functions are of the forms: Δ (O 1s - P 2p) (eV) = 375.54 + 0.146 · L(P–O) (pm) and Δ (O 1s - P 2s) (eV) = 320.77 + 0.129 · L(P–O) (pm). The dependencies are general for inorganic phosphates and may be used in quantitative component analysis of X-ray photoemission spectra of complex oxide compounds including functional groups with different coordination of P and O atoms.