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Phase stability and sintering resistance of A2Zr2O7 with three rare-earth elements at the A-site: (La0.33Gd0.33Yb0.33)2Zr2O7

2023; Elsevier BV; Volume: 44; Issue: 2 Linguagem: Inglês

10.1016/j.jeurceramsoc.2023.09.023

1873-619X

Minoo Motie-Fard, M. Bahamirian, M. Farvizi, Mohsen Nouri‐Khezrabad, Arash Faraji,

Nuclear Materials and Properties

The high sintering resistance of multi-cation zirconates has attracted a lot of research interest in new generation of thermal barrier coatings. For this purpose, La3+, Gd3+, and Yb3+ cations were selected for placement in the A-site of A2Zr2O7 structures to synthesize (La0.33Gd0.33Yb0.33)2Zr2O7 powder using co-precipitation method at 1000 °C for 3 h. The high-temperature properties of the prepared powder were evaluated at 1300 °C for 50 h. The results indicated an increase in the tendency to change the crystallographic structure from defect fluorite to pyrochlore during the heat treatment process. Compared to the single-cation zirconates, La2Zr2O7 (⁓ 4 nm.h−1), Gd2Zr2O7 (⁓ 3.5 nm.h−1), and Yb2Zr2O7 (⁓ 12 nm.h−1) powders, the (La0.33Gd0.33Yb0.33)2Zr2O7 multi-cation zirconate powder exhibited a lower growth rate of crystallite size (⁓ 3 nm.h−1). This suggests that the use of multiple cations in the A-site of A2Zr2O7 structures can be more beneficial in improving sintering resistance than using a single cation.