Flash sintering with concurrent crystallization of Li1.5Al0.5Ge1.5(PO4)3 glass

Single-phase Li1.5Al0.5Ge1.5(PO4)3 NaSICON (Na superionic conductor) glass-ceramic is obtained via a new route using flash-sinter crystallization. Green compacts of glass powder are sinter-crystallized in a few seconds. The results suggest that controlling the current increase during the flash event is needed to avoid overheating, which could cause the melting of the samples. A processing map for the flash sinter-crystallization of Li1.5Al0.5Ge1.5(PO4)3 is developed and presented based on the current density and holding time at the steady state. The samples fabricated by flash sinter-crystallization are compared with those conventionally heated. Using this novel technique, single-phase glass-ceramics are obtained with total ionic conductivity at room temperature surpassing that of glass-ceramics prepared by conventional heating (2.26 10−4 S cm−1 and 1.36 10−4 S cm−1, respectively).