Synthesis of La_(9.33)Si_6O_(26) Single-phase Ultrafine Powder by Sol-Gel Self-combustion Method

Single-phase and ultrafine La_(9.33)Si_6O_(26) powders were directly synthesized by a sol-gel self- combustion method using citric acid and ethylene alcohol as chelating reagents and fuels,nitrate as oxidant and ammonia to adjust the pH value of the system.XRD and TEM were employed for the phase identification and morphological observations of the obtained powders,which sintering performance was also studied.The results show that single-phase La_(9.33)Si_6O_(26) powders with particles sizes ranging from 150nm to 300nm can be directly and rapidly synthesized through sol-gel and self-combustion processes without ary additional thermal solid reactions on the properly selected reaction conditions.The ultrafine powders possess very high sintering activities,and can be well sintered at 200~C lower than the sintered temperature of the powders derived from conventional solid reactions.