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

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 °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. Graphical abstract: [Figure not available: see fulltext.].