Correlation between glass transition effect and structural changes in multicomponent iron phosphate-silicate glasses

Abstract

Iron phosphate-silicate glasses from P 2 O 5-SiO 2-K 2 O-MgO-CaO-Fe 2 O 3 system were subjected to the thermal and spectroscopic studies in order to gain information about their structure and thermal behavior in the range of glass transition effect. Research includes results obtained via DSC, MIR and DRIFT spectroscopy. Designated values of glass transition temperature and specific heat change slightly increases with Fe 2 O 3 incorporation. Spectra collected during thermal treatment of glasses containing 2 and 30 mol% Fe 2 O 3 exhibited various changes. Fe 2 O 3 addition affected the glass structure by its reinforcement and led to its preservation during thermal treatment. The connection between density, molar volume, oxygen packing density and the chemical composition's alteration were also established because of the direct dependence of physical properties and the structure. Obtained results supported thermal and spectroscopic studies. Conducted research is considered as a contribution to the knowledge about the family of iron phosphate glasses, which are known from their interesting properties and widely used applications.

Crystallization and Thermal Stability of the P-Doped Basaltic Glass Fibers

“…The thermal analysis data allow us to make the assumption that the most thermally stable sample is a sample containing 2 wt % phosphorus oxide. The glass transition temperature of P-BS2 varies slightly, which corresponds to literature data [21,22]. At the same time, the position of the exothermal peak corresponding to the crystallization process shifts to the higher temperature ( Figure 6).…”

“…An increase in the content of P2O5 to 6 wt % leads to a decrease in the density of glasses ( Figure 7), which may be due to the polymerizing effect of phosphorus oxide, which binds a certain amount of divalent modifier ions into M3(PO4)2 complexes and is integrated into the aluminosilicate framework. This preparation is confirmed by the literature data obtained for similar compositions [15,21]. An increase in the content of P 2 O 5 to 6 wt % leads to a decrease in the density of glasses (Figure 7), which may be due to the polymerizing effect of phosphorus oxide, which binds a certain amount of divalent modifier ions into M 3 (PO 4 ) 2 complexes and is integrated into the aluminosilicate framework.…”

“…An increase in the content of P 2 O 5 to 6 wt % leads to a decrease in the density of glasses (Figure 7), which may be due to the polymerizing effect of phosphorus oxide, which binds a certain amount of divalent modifier ions into M 3 (PO 4 ) 2 complexes and is integrated into the aluminosilicate framework. This preparation is confirmed by the literature data obtained for similar compositions [15,21]. Samples P-BS2 and P-BS6 remain amorphous at 700 °C, while a single peak of quartz appears for basalt glass fibers with 4 and 6 wt % P2O5 (ICDD No.…”

“…Iron phosphate glasses are commonly characterized by O/P ratio indicating whether orthophosphate, pyrophosphate or metaphosphate units prevail in the structure [21,22]. Authors studied the mutual influence of the components in the P 2 O 5 -SiO 2 -K 2 O-MgO-CaO-Fe 2 O 3 system in detail.…”

An Insight into the Correlation between Chemical Composition Changes of Aluminum-Iron-Polyphosphate Glasses and Thermal Properties

“…The increase in the T g temperature is related to the increase in the glass network stiffness, as defined and discussed in [ 34 , 35 ]. The network becomes more rigid, and in this way, more energy needs to be provided to start the atom reorganization and to activate the rotational motions of atoms [ 23 , 35 , 36 , 37 ]. According to our previous studies concerning the influence of aluminum on structural features of the IPG, we demonstrate that aluminum increases considerably the glass network polymerization.…”