The preparation and chemical durability study of high doped rare earth PAB glass

The phosphate glasses doped with rare earth ions have been widely used in laser mediums and optical filter materials for their outstanding optical and spectrum characteristics. The structure and its effect on the chemical durability, under different chemical solutions, based on Sm₂O₃ doped PAB (P₂O₅-Al₂O₃-BaO) glasses were investigated by MAS NMR, FT-IR and other technical methods systemically. The results shows that the main structure unit of PBAS glass is [PO₄] and [AlO₆]; with the increasing of Al³⁺ and Sm³⁺ content, the structure of glass tends to more stability, and the water resistance performance is more excellent; the corrosion of glass in acid media depends on the polarize ability (Z²/r), the acid resistance performance can be improved when the Z²/r is increasing, moreover, the dissolution rate decreases because of a hydrated layer. The corrosion mechanism of glass in alkali media is that the metal ions of phosphate long chain are hydrated; the P-O-P bond is disentangled and dissolved in the form of orthophosphate. The results display that with the increasing of Sm³⁺ ions, the alkali resistance performance decreases.