Unveiling Local Structures and Correlations in Rare-Earth Zirconates

Rare-earth A2Zr2O7 zirconates have traditionally been classified as either long-range ordered pyrochlore structures or disordered defect-fluorite structures. However, recent studies indicate that the so-called defect-fluorite phase exhibits a lower symmetry local structure. Our recent neutron pair-distribution function (nPDF) analysis suggests a continuous structural evolution across the series, with local symmetry resembling the rhombohedral structure of the Lu2Zr2O7 end-member (Fig. 1). The proposed experiment aims to investigate the evolution of the local crystal structure in two solid-solution series, capturing structural transitions from the ordered pyrochlore phase (Er2Ti2O7, Lu2Ti2O7) through the defect-fluorite region (Er2Zr2O7) to the rhombohedral structure of Lu2Zr2O7.