Chemical durability of multicomponent lanthanide zirconate solid solutions

Abstract

Multicomponent zirconate solid solutions A2Zr2O7 (A= (Sm,Yb), (Sm,Yb,Gd), (Sm,Yb,Gd,Er), and (Sm,Yb,Gd,Er,Dy)) were synthesized through spark plasma sintering and their chemical durability was investigated via semi-dynamic leaching tests in pH = 1 nitric acid at 90 °C. Incongruent dissolution occurred for all samples with the preferential elemental release of zirconium in all A2Zr2O7 except for high entropy (Sm,Yb,Gd,Er,Dy)Zr2O7 which displays a congruent release of the A-site elements and Zr. A strong positive correlation was found between the lanthanide elemental release rates and the A-site cation size disorder, whereas a negative correlation was observed between the elemental release rates and mixing entropy.