Anatomy of Flash Sintering in Yttria-Stabilized Zirconia Solid-State Electrolyte: High Temporal Resolution Energy-Dispersive X-Ray Diffraction Using a 200 Kev Synchrotron Probe

Abstract

High-energy synchrotron X-ray diffraction enables ultra-rapid data collection to determine unit cell volume evolution of 8YSZ under thermal and electric field (30 V/mm). Such an approach provides unprecedented insight into the anatomy of 8YSZ's flash sintering in the 797-810 & DEG;C interval. The densification due to flash sintering occurs in 40 s during which X-ray spectra were collected every 2 s. The densification of 8YSZ was accompanied by 0.55% anelastic peak shift on (220) reflection. Concomitantly, the applied thermal and electric field led to anelastic expansion of the cubic lattice parameter (+ 0.55%) and unit cell volume (+ 1.57%). Besides, an irreversible increase in the peak intensity (+ 22.6%), a decrease in peak width (- 18.3%), and integrated peak (- 13.6%) are determined. The observed anomalies are attributed to the response of oxygen vacancy generation and redistribution to the combined electric and thermal fields.