Order-disorder transition and electrical performance of (Nd_1–xY_x)₂Zr₂O₇ solid solutions

(Nd_1–xY_x)₂Zr₂O₇ solid solutions have been prepared by solid phase method. The influence of yttrium content on the structure and electrical performance has been explored. The crystal structure is characterized by X-ray diffraction and Raman spectroscopy. The morphology is investigated by scanning electron microscopy. The electrical property is analyzed by electrochemical impedance spectroscopy measurement. (Nd_1–xY_x)₂Zr₂O₇ solid solutions exhibit a single-phase structure except that NdYZr₂O₇ shows a biphasic structure. As yttrium content x raises from 0 to 1, the order degree of (Nd_1–xY_x)₂Zr₂O₇ solid solutions decreases gradually, and the structures of solid solutions transform from ordered pyrochlore-type structure to disordered defect fluorite-type structure. (Nd_1–xY_x)₂Zr₂O₇ solid solutions are dense, and the relative densities are over 94%. The total conductivity of Nd₂Zr₂O₇ is greatly enhanced by doping yttrium at the Nd-site in 823–1073 K. The total conductivity achieves 5.2 × 10⁻³ S cm⁻¹ at 1073 K for (Nd_0.6Y_0.4)₂Zr₂O₇, which is the highest valve of (Nd_1–xY_x)₂Zr₂O₇ solid solutions.