Thermal properties of Na2O–P2O5–Fe2O3 polyphosphate glasses

Abstract

Iron phosphate glasses are materials that can have many applications like durable matrixes in waste immobilization techniques, biomaterials, optoelectronic devices, etc. Their possible usage is related to their glass network and thermal properties. The influence of Na 2 O content on thermal properties and crystallization ability of iron phosphate glass of base composition 30 Fe 2 O 3 -70 P 2 O 5 mol% were studied. Increasing the content of Na 2 O causes a decrease in transformation temperature and increase in ΔC p . Characteristic temperatures, thermal stability and crystallizing phases were determined. Increasing content of sodium causes depolarization of iron phosphate glass network which causes a continuous change in ΔC p and glass transformation temperature. Discontinuous change in some glass properties suggests structure rebuilding about 30 mol% of Na 2 O.

Thermodynamic model and Raman spectra of MgO–P2O5 glasses

“…This large variability in composition makes phosphate glasses excellent candidates for various applications, namely in the field of metals sealing, photonics, medical and health care, vitrification of radioactive waste, etc. [5][6][7][8][9][10][11].…”

Structural stability and proton beam irradiation effects on simulated metal fluoride waste–loaded iron phosphate glass

“…Both Ce 3+ and Nd 3+ and also Ca 2+ are reportedly known to act as glass formers, whereas alkali metals like Na + mostly act as network modifiers. 8,11 Contrasting effects of these loaded cations together with effective O/P determine the relative fraction of the different Q n tetrahedra in the different samples. In comparison, Nd 3+ -and Sm 3+ -loaded samples exhibit network with shorter chain lengths.…”

“…7 However, it has been reported that the addition of Na 2 O-IPG generally leads to depolymerization of the glass network, which adversely affects its stability. 8 Moreover, Fe 2 O 3 addition to sodium aluminophosphate glass loaded with a mixture of metal fluorides (CsF, SrF 2 , ZrF 4 , CeF 4 , and SmF 3 ) leads to decrease in the phosphate chain length but improvement in chemical durability. 9 It has been argued that when oxygen is replaced with fluorine atom, the network connectivity in phosphate glass is decreased.…”

“…The choice of the former salt is because it is commonly used in combination with LiF and KF in the secondary loop of the MSR 7 . However, it has been reported that the addition of Na 2 O–IPG generally leads to depolymerization of the glass network, which adversely affects its stability 8 . Moreover, Fe 2 O 3 addition to sodium aluminophosphate glass loaded with a mixture of metal fluorides (CsF, SrF 2 , ZrF 4 , CeF 4 , and SmF 3 ) leads to decrease in the phosphate chain length but improvement in chemical durability 9 .…”

Effect of Dolomite Addition on the Structure and Properties of Multicomponent Amphibolite Glasses

“…The increase of metal ions in coordination number 4 results in the incorporation of these ions into the glass bond, thus strengthening it, which contributes to an increase in the stability of glass with 20% dolomite addition [53]. According to literature data, the higher K H value for glass, the higher its resistance to crystallization during heating and ability to vitrify during cooling [54,55]. A lowering of the K SP , K A , and K H values implies a higher ability to crystallize, which is particularly important during the lifetime of the glasses, depending on their intended use.…”