Magnetization, rutherford backscattering spectroscopy (RBS), and X-ray photoelectron spectroscopy (XPS) studies of manganese-phosphate glasses

Phosphate glasses containing MnO₂ with nominal composition [(MnO₂)_x (P₂O₅)_1-x], x = 0.10, 0.15, 0.20, 0.30, and 0.40 were studied by magnetization, Rutherford backscattering spectrometry (RBS), and X-ray photoelectron spectroscopy (XPS). It is observed that compositional changes take place in going from batch to glass and that the changes are more pronounced for low Mn concentration. The ratio [Mn²⁺/Mn_total] as a function of x was determined from the magnetization data combined with RBS results. However, unambiguous values of the ratio could not be determined from the XPS studies. In the XPS study of these glasses, one notable feature of the Mn 2p spectra is the shift in the 2p peaks to higher binding energy compared with MnO₂ powder. Perhaps formation of metal phosphates could be the dominant process responsible for the high energy shift of the metal 2p levels.