Effects of Nd Content on Structure and Chemical Durability of Zirconolite–Barium Borosilicate Glass‐Ceramics

The effects of Nd 2 O 3 content (0–12 wt %) on crystalline phases, microstructure, and chemical durability of barium borosilicate glass‐ceramics belonging to SiO 2 –B 2 O 3 –Na 2 O–BaO–CaO–TiO 2 –ZrO 2 –Nd 2 O 3 system were studied. The results show that the glass‐ceramics with 2–6 wt% of Nd 2 O 3 possess mainly zirconolite and titanite phases along with a small amount baddeleyite phase in the bulk. Calcium titanate appears when the Nd 2 O 3 content increases to 8 wt%, and the amount of quadrate calcium titanate crystals increases with further increasing content of Nd 2 O 3 . For the glass‐ceramics with 6 wt% Nd 2 O 3 (Nd‐6), Nd elements homogeneously distribute in zirconolite, titanite, and residual glass phases. There is a strong enrichment of Nd in calcium titanate crystals for the sample with 10 wt% Nd 2 O 3 . The viscosity of Nd‐6 glass is about 49 dPa·s at 1150°C. Moreover, Nd‐6 glass‐ceramics show the lower normalized leaching rates of B ( LR B ), Ca ( LR C a ), and Nd ( LR N d ) when compared to that of the sample with 8 wt% Nd 2 O 3 . After 42 days, LR B , LR C a , and LR N d of the Nd‐6 glass‐ceramics are about 6.8 × 10 −3 , 1.6 × 10 −3 , and 4.4 × 10 −6 g·m −2 ·d −1 , respectively.