Structure, mechanical, and chemical performance evolution of aluminosilicate glass modified by Nd 2 O 3

In this paper, the simulated nuclear waste was successfully immobilized by using aluminosilicate glass made from natural granite material without other additive agents. The neodymium-doped matrix’s phase composition, microstructure, element distribution, hardness, density, indentation fracture toughness, and aqueous durability were analyzed. The results show that the samples with a neodymium content of 10 wt.% are fully vitrified and reach the maximum neodymium solubility. The silicate tetrahedra of glass networks mainly exist in sheets ( Q 3 ) and frame ( Q 4 ) units. Neodymium oxide acts as a glass modifier and destroys the sheet form and may precipitate metal elements in the matrix, resulting in a Vickers hardness of up to 8.17 GPa for this aluminosilicate glass. However, the indentation fracture toughness decreases. Moreover, NR Nd is about 10 −7 ~ 10 −8 g·m −2 ·d −1 during the 28-day aqueous durability test, indicating its excellent aqueous durability. This work provides a new idea for immobilizing radionuclides via glass.