Thermoluminescence, elastic and dielectric investigations of calcium fluoro borophosphate glass composite materials doped by small concentrations of TiO2

State of the Art Review for Titanium Fluorine Glasses and Glass Ceramics

“…The literature indicates varying trends with respect to the effects of increasing Ti content on the density and network connectivity of Ti- and F-containing glasses. For instance, increased density and network connectivity (upon the addition of Ti) occurred in networks where the primary glass-forming system was borophosphate [ 16 ], phosphate [ 18 ], and borosilicate [ 19 ]. Specifically in phosphate and borophosphate glasses, the addition of TiO 2 has been shown to strengthen the network by creating cross-links between phosphate and borate chains (P-O-P and B-O-B linkages are substituted by P-O-Ti or B-O-Ti linkages), thus increasing the bulk density [ 16 , 18 ].…”

“…For instance, increased density and network connectivity (upon the addition of Ti) occurred in networks where the primary glass-forming system was borophosphate [ 16 ], phosphate [ 18 ], and borosilicate [ 19 ]. Specifically in phosphate and borophosphate glasses, the addition of TiO 2 has been shown to strengthen the network by creating cross-links between phosphate and borate chains (P-O-P and B-O-B linkages are substituted by P-O-Ti or B-O-Ti linkages), thus increasing the bulk density [ 16 , 18 ]. Similarly, an increase in the number of bonds per unit area and the cross-linking density was observed with increasing Ti content in borosilicate glasses [ 19 ].…”

“…The findings derived from the literature [ 14 , 18 , 19 , 65 ] agree with the reported trends in coordination numbers summarized above, wherein a decrease in coordination number is often associated with a decrease in network connectivity. Only two articles [ 15 , 16 ] reported the effects of Ti addition on the density and network connectivity of a glass with the same glass-forming system, i.e., borophosphate. Contrary to the findings of Guntu et al [ 16 ] discussed above, Rua and Kumar [ 15 ] found that an increase in TiO 2 content caused an increase in non-bridging oxygens, which induced higher grades of disorder within borophosphate networks and resulted in a decreased network connectivity.…”

“…Only two articles [ 15 , 16 ] reported the effects of Ti addition on the density and network connectivity of a glass with the same glass-forming system, i.e., borophosphate. Contrary to the findings of Guntu et al [ 16 ] discussed above, Rua and Kumar [ 15 ] found that an increase in TiO 2 content caused an increase in non-bridging oxygens, which induced higher grades of disorder within borophosphate networks and resulted in a decreased network connectivity. These two articles [ 15 , 16 ] observed opposing and contrasting results, which emphasize the difficulties associated with predicting the effects of Ti and F inclusion in certain glass systems.…”

“…Materials consisting of mixed valence state Ti ions are also probable candidates as cathode materials for photoelectrochemical cells (PECs) [ 15 ]. Additionally, TiO 2 polymorphous materials are large bandgap semiconductors (3.2 eV) and, due to their high storage capability, cycling stability, and charging/discharging rate, are considered useful for use as electrode materials for lithium-ion batteries in photocatalysis and in solar cells [ 15 , 16 ]. Furthermore, the addition of Ti to glass and glass-ceramic materials has also been shown to increase chemical durability, thermoluminescent sensitivity, thermal stability, and the mechanical properties of glasses and glass ceramics.…”