Thermal stability of glasses from the Fe4(P2O7)3–Fe(PO3)3 system

Iron phosphate glasses with nominal Fe/P compositions between 0.50 and 0.67 were prepared and characterized. The effects of melt conditions and the initial composition on the Fe(II)-content are reported. Characteristic temperatures, including the glass transition temperature and crystallization temperature, were measured by DSC. The stability of melts against crystallization, described by the Angel and Weinberg parameters, generally decreases with increasing O/P and Fe/P ratios.