CC BY 3.0 DEMatthai, AnnegretDoris, EhrtRüssel, Christian2024-01-082024-01-081998https://oa.tib.eu/renate/handle/123456789/14173https://doi.org/10.34657/13203Glass melts and glasses with the basie composition NaPO₃ · 2Sr(PO₃)₂ doped with V₂O₅ and Fe₂O₃ were studied with the aid of square-wave voltammetry and spectroscopic methods. From the square-wave voltammetry in the glass melt, a linear dependence of the peak potentials on the temperature was obtained. The Standard enthalpy ΔH⁰, the Standard entropy ΔS⁰ and lg(C_ox/C_red) of the transitions Fe³⁺/Fe²⁺ and V⁴⁺/V³⁺ were calculated. The diffusion coefficients calculated from the peak currents measured follow Arrhenius' law. By means of electron spin resonance, the concentration of V⁴⁺ was determined. The corresponding extinction coefficients for the V⁴⁺ bands were calculated from the absorption spectra. Concerning the vanadium-containing glass, the results of square-wave voltammetry and spectroscopy were compared quantitatively. For the iron-doped glass, the comparison was only qualitative.enghttps://creativecommons.org/licenses/by/3.0/de/660Redox behaviour of polyvalent ions in phosphate glass melts and phosphate glassesArticle