ABSTRACT
(Mg, Co, Ni, Cu, Zn)1-xLixO is a type of high-entropy oxide that has high ionic conductivity at room temperature and is used as a solid electrolyte. (Mg, Co, Ni, Cu, Zn)1-xLixO was successfully synthesized from precursor powder by applying reactive flash sintering for less than 4 min at room temperature (25 °C). AC and DC electric fields were independently applied to sinter ceramic samples; consequently, AC and DC electric field application resulted in relative densities that exceeded 90% and 80%, respectively. X-ray diffraction spectra of samples revealed the existence of a clear halite structure with an insignificant impurity phase, proving that (Mg, Co, Ni, Cu, Zn)1-xLixO crystals were successfully produced.
ABSTRACT
Ceramic flash sintering with a strong electric field at room temperature is the most attractive method. This paper presents the flash sintering of ZnO ceramics at room temperature by the application of a 3-kV/cm electric field after a dropwise addition of ethanol. This method is simple and easy to control. The density of the specimen exceeded 96% after 30 s of sintering. No significant difference was observed in the initiation voltage of flash sintering with and without the dropwise addition of ethanol. Ethanol burns upon dropwise addition, causing a discharge to first occur far from the location of the dropwise addition, followed by glowing and heating up, which causes the temperature of the entire specimen to rise.
