Ultrasonic Spray Co-precipitation To Prepare YAG Nano-powders

Yttrium aluminum garnet (YAG) has excellent mechanical, thermal and opticalproperty, which is a promising material used as phosphors media, laser media andadvanced structural material. The latest research find that, compared with YAG singlecrystal, polycrystalline YAG ceramic is low cost, can be highly doped with Nd3+andpossible for lager size and high power laser polycrystalline. Thus YAG ceramicbecome an important development direction in high-performance solid-state lasermaterial. To prepare the high-density and high-transparency polycrystalline YAGceramic, the fabrication of highly-dispersed ultra-fine YAG powders are necessaryand become one of the hotspots in recently study.In this work, ultrasonic spray co-precipitation method was used to synthesize theYAG nano-powders which included aerosol formation ultrasonically from yttrium andaluminum mixture and co-precipitation processes. The effects of different ultrasonicspray devices, spray droplets reaction path, calculation temperature and holding time,different aluminum ion concentration on the properties of ultra-fine YAG powderswere studied to find out the best preparation of the transparent YAG ceramic powders.Detailed phase and structural analyses were carried out using TG-DSC thermalanalysis, X-ray powder diffraction (XRD) and scanning electron microscopy (SEM).The results show that the well-dispersed YAG nano-powders can be prepared bythis ultrasonic spray co-precipitation method. As ammonia was used as theprecipitation agent in the case of top symmetric spray, the amorphous precursorcalcined at1000℃for3h with high metal ions concentration (CAl3+=0.5mol/L) can beconverted to crystalline Homogeneously. The average size of YAG particles wasabout50nm and well-dispersed. As ammonium hydrogen carbonate was used as theprecipitation agent with300w ultrasonic device to prepare the nano YAG powders,the average size of YAG particles after calculated was about30~40nm andbetter-dispersed.