Study on the chemical durability of high doped rare earth phosphate glass

As the Laser medium and special type optical glass materials, the chemical durability of phosphate glass doped with rare earth is important. In this paper, the chemistry stability was studied on P₂O₅-BaO-Al₂O₃ system glass doped with 10mol% and 15mol% Sm₂O₃. The results showed that with the increasing of Al³⁺ and Sm³⁺ content, the structure of glass tended to be more stability, and the water resistance performance was more excellent. Corrosion of the glass in acid media depended on the polarize ability (Z²/r), and the acid resistance would be improved when the Z²/r was increasing, moreover, the dissolution rate decreased because of a hydrated layer. The corrosion mechanism of the glass in alkali media was that after the metal ions of phosphate long chain were hydrated, the P-O-P bond was disentangled and dissolved in the form of ortho-phosphate. The results displayed that with the increasing of Sm³⁺ ions, the alkali resistance performance decreased.