Flat-elongated-granulated complex morphology with (002) preferred orientation and high sinter activity of AZO nanoparticles by ethanol-assisted coprecipitation

Aluminum zinc oxide (AZO) nanoparticles were successfully synthesized by a facile and environment friendly ethanol-assisted coprecipitation method. The other two coprecipitation methods were studied to obtain AZO nanoparticles using the same granular Zn but different processes (i) homogeneous coprecipitation and (ii) seed-induced coprecipitation simultaneously for comparison. The AZO precursor prepared by ethanol-assisted coprecipitation displayed the unique endothermic heat behavior which was different from the other two counterparts, leading to the hexagonal ZnO structure with (002) crystallized preferred orientation and flat-elongated-granulated complex morphology after calcination at 600 °C, exhibiting outstandingly higher sinter activity than other two counterparts, and achieving a nearly full relative density (99.1%) of AZO ceramic at only 1200 °C through the traditional pressureless sintering technique. The mechanism of crystallized preferred orientation of AZO nanoparticles and sintering densification of AZO ceramics were lastly proposed.