K-BETA X-RAY-EMISSION SPECTRA OF PHOSPHORUS OXO ACIDS AND ANIONS

With a high-resolution two-crystal vacuum spectrometer, the phosphorus K beta emission spectra in fluorescence are measured for H3PO3 (=H2PHO3), H3PO4, Li3PO4, Na3PO4 . 12H(2)O, Na2HPO4, NaH2PO4, K3PO4 . nH(2)O, K2HPO4, KH2PO4, Ca-3(PO4)(2), CaHPO4 . 2H(2)O, Ca(H2PO4)(2) . H2O, CaHPO3 . H2O, Ca(H2PO2)(2) and NH4H2PO4. In the phosphate compounds, a weak peak is observed on the high-energy side of the main peak K beta(1) and related to a molecular orbital of t(2) symmetry in the PO43- ion. It is shown that the phosphorus K beta emission spectra are influenced by ligand substitution and cations. The measured KP emission spectra of Li3PO4, Na3PO4 . 12H(2)O, K3PO4 . nH(2)O and Ca-3(PO4)(2) are presented along with the previously reported P-K absorption spectra of these phosphate compounds. The emission and absorption spectra are interpreted in terms of available molecular orbitals of the PO43- ion.