Phase evolution in oxy-fluoride glass ceramics

Transparent oxyfluoride glass ceramics

“…In a similar manner, a study of phase transformations during SiO 2 -Al 2 O 3 -CdF 2 -PbF 2 -ZnF 2 -ErF 3 glass crystallization showed that -according to XRD analysis data -samples, annealed at T g , were still X-ray amorphous, and no crystalline phase were observed in them [135]. Sample crystallization was observed in the specimens annealed at 10 o C higher than the first exo-thermic peak temperature (T с1 ), and the first phase to crystallize was fluorite-type PbF 2 .…”

Crystallization kinetics of fluoride nanocrystals in oxyfluoride glasses

“…Thus, merits of oxide glass and fluoride can be obtained at the same time in the oxyfluoride glasses. The primary crystallization that is the formation of fluoride nanocrystals in the silicate glass matrix should occur rapidly, while the secondary crystallization that is the formation of another crystalline phase after the primary crystallization of fluorides should occur slowly, since the secondary crystallization will seriously deteriorate the transparency of the matrix [17]. Glass working to fabricate the optical devices should be completed before the second crystallization initiates.…”

New Nanoglassceramics Doped with Rare Earth Ions and Their Photonic Applications

“…For a long time there was a common opinion that only the fluorine-containing materials (like fluoride glasses and crystals) are optimal for the said problem solution. However, since recently the synthesis of the glassceramics materials like the oxifluoride silicate glasses has become the priority direction of studies [16][17][18][19][20][21][22][23][24]. Such composite materials combine the optical parameters of the low-phonon fluoride crystals and the good mechanical and chemical features of the silicate glasses.…”

“…In [17] on the base of spectroscopy and X-ray phase data was concluded that the erbium-containing crystalline phase is a solid solution of erbium fluoride in β-PbF 2 . In [18] there was investigated the separation of the crystalline phase during heat treatment of the glasses 50GeO 2 -40PbO-10PbF 2 . Their heat treatment has resulted in separation of the fluorite-like phase.…”